How many men would it take to invade and control a planet?

[Warsie]

The Hoth tactical shield was powerful enough that 5 ISDs and a Executor could not bring it down.

Technically, that was a new, special type of shield a bunch of scientists on Ralltiir designed (source: Rogue Squadron 3)

[Surlethe]

The Hoth tactical shield was powerful enough that 5 ISDs and a Executor could not bring it down.

Technically, that was a new, special type of shield a bunch of scientists on Ralltiir designed (source: Rogue Squadron 3)

Does that necessarily refer to amount of firepower withstood?

[Warsie]

Does that necessarily refer to amount of firepower withstood?

I believe so...in the mission 'Defiance on Dantooine' Tycho says that "the shield is the only reason the Empire didn't take them yet"

EDIT: Also, one of the things, if enemy fleets bombard worlds, they risk being shot down by any turbolasers on the planet. It seems that they have to 'stay still' or go decently close that the turbolasers can shoot at them with good aim.

[Jim Raynor]

Orbital fire and advanced technology will allow SW troops to cover much more ground than their real-life Earth counterparts could. However, you can't slag every city where you encounter resistance. The Empire probably would do that sometimes to make a few examples, and even it has limits on the level of brutality it could resort to. For other SW factions like the Republic, Rebels, etc., it would be even harder for them to take and effectively hold a planet. I think at least several tens of millions of troops would be needed to occupy a planet with a population of several billions. If there's widespread insurgency, you would need more. I think a couple million is way too small.

[Surlethe]

I believe so...in the mission 'Defiance on Dantooine' Tycho says that "the shield is the only reason the Empire didn't take them yet"

Perhaps I wasn't clear enough. Does the fact it was specially designed necessarily refer to the amount of fire it can withstand, or does it refer to something else, like perhaps power efficiency or portability?

EDIT: Also, one of the things, if enemy fleets bombard worlds, they risk being shot down by any turbolasers on the planet. It seems that they have to 'stay still' or go decently close that the turbolasers can shoot at them with good aim.

Note that "decently close" is several AU. The guns on a Venator are able to hit a target with reasonable accuracy at up to 10 light-minutes.

[Warsie]

Perhaps I wasn't clear enough. Does the fact it was specially designed necessarily refer to the amount of fire it can withstand, or does it refer to something else, like perhaps power efficiency or portability?

I don't know. They don't go into detail on the shield in Rebel Strike, as far as I can see.

Note that "decently close" is several AU. The guns on a Venator are able to hit a target with reasonable accuracy at up to 10 light-minutes.

Yeah, true. The turbos can still hit the ships, though. the source is the RTS game Rebellion.

[Ghost Rider]

The Hoth shield was mentioned in the "Inside the Worlds" as a ripped out shield generator from a large crusier(I'll have to check).

Also, note Vader's want. When Veer's goes "Deflect any bombardment", the Radio Drama makes it clearer by indicating it was "Clean". Meaning if they start to go at it...it would likely kill Skywalker, and piss Vader off something fierce. This also falls perfectly in line with Ozzel being a fuck up by coming in too close.

As for range. The Venators doing light minutes easily outdoes anything Rebellion has to say on the issue, and more so...a planet's TLs are at a disadvantage by the sheer fact they only have so much sky at their disposal.

[Warsie]

The Hoth shield was mentioned in the "Inside the Worlds" as a ripped out shield generator from a large crusier(I'll have to check).

That was a reactor from a Procurator-class I believe, actually.

Also, note Vader's want. When Veer's goes "Deflect any bombardment", the Radio Drama makes it clearer by indicating it was "Clean". Meaning if they start to go at it...it would likely kill Skywalker, and piss Vader off something fierce. This also falls perfectly in line with Ozzel being a fuck up by coming in too close.

Right. That's also in the novelization, right?

As for range. The Venators doing light minutes easily outdoes anything Rebellion has to say on the issue, and more so...a planet's TLs are at a disadvantage by the sheer fact they only have so much sky at their disposal.

That's a matter of overriding something, Right? Also, the ground turbo disad is mentioned in SW: Rebellion. Each gun can only damage (or destroy; depending on ship hull) one ship per bombardment.

[Doshniel]

The Torpedo Sphere, a dedicated siege platform, is designed to accomplish one mission - to knock out a planet's shields. Planetary shields, whether full or partial, protect a world from orbital bombardment. It takes a lot of troops to assault a planet. It is easier and far less expensive to simply pound a planet into submission with the weapons of a Star Destroyer. But planetary shields prevent this.

I'm no military genius and I don't pretend to be one, but who in their right mind would allow something like a torpedo sphere to destroy a planet's shield. Sure I can see that it will be useful on some primitive defense without backup defenses, but no way can I even for a second believe it would work on a well defended world.

To begin with their is absolutly no reason whatsoever to not make sheild within the planetary shield, whose sole purpose it is to protect the shieldgenerators. Perhaps this shield would require some sort of shield generator as well, but I don't see the problem with that either. In fact it seems very logical. There are many practical reasons for makeing this smaller shield less energy consuming then the larger shield and this is probably easily managable considering what a little area it must cover.

Then ofcourse you could simply use planetary weaponry to shoot down any siege engines placed around the orbit of the planet. The point being, that there's no reason whatsoever to build a freakin planetary sheild, if all that is required to destroy is one advanced siege engine. No point whatsoever, unless it takes an enormous amount of time for this siege engine to get through the planetary defense.

YES! A large army is needed. A ground assault!
For this purpose you need millions of troops, but probably not more then ten million for a world of five billion people. Sure, it could require a lot more then that, depending upon various factors such the planets composition, how many cities the planet has, how the planet is controlled and how many fortifacations are built across its surface. Then it could a planet that had seen a lot of coremining and worse. Such a planet would be filled with so many tunnels that it would truly never be conguered. Guerilla warfare would continue forever.

Then we have djungle planets. Dense jungleplanets with enormous forests stretching as far as the eye can see. Of course there is no way to easily conguer this planet, but then do you really have to?
All you really want is the planets spacecapabilities and once those are under your control, the enemy can live in their jungle for decades if they so wish.

conguering the galaxy is a messy buisiness, especially if you want to conguer every squaremile on every planet. Much better to just claim all spaceports and as many starships as possible.

[Doshniel]

Sorry for all the spelling mistakes, I will correct a few of them.

To begin with there is absolutely no reason whatsoever to not make shields within the planetary shield.

Then I believe conquering is wrote with a bloody q, not a g, but anyways I'll settle for those corrections.

[Warsie]

The point being, that there's no reason whatsoever to build a freakin planetary sheild, if all that is required to destroy is one advanced siege engine. No point whatsoever, unless it takes an enormous amount of time for this siege engine to get through the planetary defense.

Shields are good if asteroids hit, and they can keep the enemy from landing troops on your world/keep ships form bombarding.

Then it could a planet that had seen a lot of coremining and worse. Such a planet would be filled with so many tunnels that it would truly never be conguered. Guerilla warfare would continue forever.

Couldn't they blockade and starve the guerillas out into surrendering? The Empire did that (unsuccessfully) with Ralltiir and some other worlds.

Then we have djungle planets. Dense jungleplanets with enormous forests stretching as far as the eye can see. Of course there is no way to easily conguer this planet, but then do you really have to?

If it's a jungle world, they would try to take the areas of civilization. And it the side is real mean, they could bombard and burn the entire forest doen with Orbital bombardment.

All you really want is the planets spacecapabilities and once those are under your control, the enemy can live in their jungle for decades if they so wish.

They is in a way true, but you need troops on the ground to enforce your will on them.

[Ritterin Sophia]

They don't just use one Torpedo Sphere, they use multiple, and they're rather large.

[Fingolfin_Noldor]

Supposedly, the torps are quite powerful. I believe one Grand Admiral held out with a torpedo sphere in Corellia until... an Executor class Star Dreadnaught rammed it and destroyed both.

A very wasteful exercise of resources.

[PainRack]

No, he won't. By virtue of being under spaceborne attack, the defender on the planet is cut off from reinforcement, while the attack can assemble resources from the rest of the galaxy very rapidly by use of hyperdrive. The attacker can draw on the resources of multiple planets, while the defender has only what is at hand.

Moreover, simple geometry prevents the defender from bringing his firepower to bear effectively; the attacker has the high ground from orbit, while the horizon allows the defender to use only a very small portion to affect the ground battle.

Excuse me. Why must the defender be utterly cut off from space reinforcements? Any battle between two galactic powers will mean contested fleets and ground units.

But the real reason that your WWIII example doesn't work is because of the power of SW orbital observation. With their level of technology, they would almost certainly have the ability to observe movements of even very small forces, and any such forces moving in the open would be immediately annihilated. Meanwhile, the first act of the attacker would necessarily be the trivially easy operation of clearing the planetary orbit of any satellites or installations capable of offering this kind of observation to the defender. Whereas in WWIII NATO and WARPAC forces would be on similar observational footing, the defender in our scenario is blind and the attacker can see everything.

And the inverse applies. Orbital observation of ground forces can be hindered by surface firepower and sensor jamming. Similarly, dispersed ground forces are relatively easy to conceal.

You're blithely assuming that an invader must have space superority in order to invade a planet. We already noticed from the Clone War era that relief missions by the Republic were conducted in conditions where space forces were still battling.Praestilyn had a naval battle rage in the system between the Confederation and the Republic, denying reinforcement for the Seperatists and firepower for the Republic. The invasion of Geonosis was conducted where an viable enemy fleet was still present, albeit one mostly consisted of transports and caught by surprise.

The attacker's superiority in firepower and his ability to see where it would be most effectively applied forces the defender into immobile fortification, either behind planetary shielding or by hiding in subterranean fortresses. These forces are incapable of maneuver and are thus incapable of affecting the course of the campaign. Doubly so for those not protected by shields, because even the direst earthworks are a joke against turbolasers--those forces can't even shoot for fear of destruction.

You assume that dispersed forces will remain immobile, yet, the Rebel Alliance was able to field such guerilla units against the Empire.

A land invasion would presuppose a siege campaign against orbital defenses which, given time, would be irresistible. It would be superficially similar to the medieval siege practice of methodically opening breaches in walls in preparation for an overwhelming assault. The idea that the highly limited arsenal of fixed planetary defense turbolasers could "contest" space forces is ludicrous and is not supported by any canon literature. These guns can cause damage to besieging forces and even drive off raiding enemies, but to a determined attack in strength, they're only an annoyance.

Except that planets in the SWU are not just defended by guns alone, but also by a mobile space fleet. As long as an intergrated space/ground defence exists, you're not going to get a massive firepower/mobility advantage. The Republic surprise attack against Geonosis, which granted them mobility in shifting their ground forces when the Geonosian airbases and fixed installations were destroyed still required a significant force to "play" around with when fighting dispersed Geonosian units.
If such installations still exist, one can very well imagine that a much larger ground force would had been required.

If a fleet is committed to siege operations against such a well defended world, then the defences has already fulfilled their purpose by tying down an enemy opponent at a single planet, leaving the board open for a stragetic move.

More importantly, you assume that armies must only face local units on a planet. What about relief missions? Armies deploying to defend a invaded planety not only make the task of invasion more difficult, armies capable of launching such a mission must be more capable, and thus more numerous.

Also, barring exceptionally wealthy planets like Coruscant, shields and fixed guns will only cover a very small portion of a planet--a few key cities and installations. These cities can then be isolated from one another by setting up a large free-fire zone around each, which is scorched by bombardment, and then picked off piecemeal as with Hoth.

Define exceptionally wealthy. Alderaan, Nar Shadaa both had planet encompassing shields. Nar Shadaa shields were weak and poorly maintained, but there is no reason to disbelieve this was due to neglect. Especially since the shields were renovated after the battle itself.

Why must the entire planet be covered by dispersed forces? The defender will be limited to those strongpoints he can defend with shields, the rest of the planet is completely at the mercy of orbital firepower and effectively irrelevant. If one captures all the strategic objectives, the number of enemies hiding out in tunnels matters not one whit, because those forces are a mass of individual units. If they maneuver, it must be done in units small enough to remain unseen or to present unappealing targets for bombardment--units too small to meet the attacker in decisive battle. If they are to be large enough to fight, they can't move without revealing themselves, and in any case they would be destroyed shortly after engaging anyway. Attacking probes that met strongpoints not protected by shields would break contact and call down the guns.

Because such scattered forces prevent you from asserting control over a planet. The Republic was forced to station a garrison on Geonosis to deal with such scattered units.

Defending mobile forces could easily be annihilated by bombardment of an environmentally friendly firepower, especially considering the likely "cleanup" capacity of the SW civilization. A brief burst of 10 kiloton light turbolaser bolts landing in the middle of a corps-sized formation would turn it into hamburger and the sun would still rise in the morning. After a long campaign of this, the planet would probably be a mess, but uninhabitable? Unlikely.

And given the highly accurate and effective weapons of SW defences, any spacecraft that attempts to use such firepower would be wiped out. Ground weapons would need to be defended from commando actions, which require a large security force.

Wrong.

Wrong.

WRONG.

Oh bollocks. You claimed that torpedo spheres were capable of scanning when the shields DROPPED and attacking at that precise moment. I countered that their role was to scan for weakness and weakens the shield, opening the shield up to attacks by other craft. I forgotten that the torpedo sphere had the turbolasers neccesary, you bloody outright misled everyone by claiming the spheres can shoot through split seconds opening.

Because there were NO enemy interceptors in place, and many ships were out of place in their assigned positions.

Of course, that means that Luke fought with ghost TIEs when leaving the planet right? The fact that there are little fighters is not equal to there being NONE.

And what about the fuel to run said shields? Or do star wars armies have magical zero point energy production?

Except that X-wings already contain an absurd amount of power and fuel for their operations. SW energy density is high enough that waiting for fuel to be exhausted is just too slow.

Wow, I guess the Empire's going to have to really scrape the barrel for on average 30 ships, when the average sector group has 1,600 combat starships and the Empire has at it's control thousands of sector groups.

This is a goddamn red herring Mk. If the question is Empire vs Rebel Alliance, then you have a point. But since the question also covers CIS vs Republic and the troops required to invade, then comparing the juggernaut of the Galactic empire to the miniscule Rebel Alliance is just misleading.

Now you're just reaching here.

You forgot that there are survivors of Dankayo and even Caamaas. You underestimate the efficiacy of SW environmental systems.

[Warsie]

Supposedly, the torps are quite powerful. I believe one Grand Admiral held out with a torpedo sphere in Corellia until... an Executor class Star Dreadnaught rammed it and destroyed both.

A very wasteful exercise of resources.

But supposedly, Torpedo Spheres are vulnerable to the point that Imperial Admirals would llegally steal (well, borrow) ISDs from the local Moffs without notice.
http://starwars.wikia.com/wiki/Torpedo_Sphere

Yeah. Grunger and Pitta blew each others' brains and fleets out
http://starwars.wikia.com/wiki/Battle_o ... vil_War%29

[MKSheppard]

I forgotten that the torpedo sphere had the turbolasers neccesary, you bloody outright misled everyone by claiming the spheres can shoot through split seconds opening.

What part of this did you miss?

That is the quick version. In reality, it takes almost a hundred heavy weapons technicians to coordinate the tube launches. The target area rarely exceeds a six meter square. The hole this produces is actually a power surge that only lasts a few microseconds. If the turbolasers have not made their shots in this time, the process must start all over again.

Wow, that sounds like "can shoot through split second opening".

Of course, that means that Luke fought with ghost TIEs when leaving the planet right? The fact that there are little fighters is not equal to there being NONE.

Wait Wat? Wait WAT?

Luke never fought with TIEs at all. You must have the super seekrit Singapore-only edition of ESB. All Luke does was take off from Hoth and fly straight to Dagobah.

Except that X-wings already contain an absurd amount of power and fuel for their operations. SW energy density is high enough that waiting for fuel to be exhausted is just too slow.

Wrong.

From the Rebel Sourcebook:

Starfighters are extremely expensive to fuel and keep in operating condition. A starfighter requires expensive fuel cells for power. The most efficient fighters drain their power after a few short weeks of standard flying - and the same amount of energy is exerted in just under an hour of combat flight.

This is a goddamn red herring Mk. If the question is Empire vs Rebel Alliance, then you have a point. But since the question also covers CIS vs Republic and the troops required to invade, then comparing the juggernaut of the Galactic empire to the miniscule Rebel Alliance is just misleading.

Except that the Republic and CIS also have absurd quantities of ships available by the mid-point of the Clone Wars.

You forgot that there are survivors of Dankayo and even Caamaas. You underestimate the efficiacy of SW environmental systems.

Actually, If I remember right, the only survivors were in deep core bunkers, e.g. bunkers deep within the planet's crust or mantle. If you have to dig that deep to survive, then that's not an economically feasible fortification.

[Imperial Overlord]

Torpedo Spheres take a considerable amount of time to do their scans and take down planetary shields. This really doesn't change much in the Star Wars universe when a task force can go from the Core to the Outer Rim in hours. If a seige lasts weeks, which is about how long it takes a torpedo sphere to do its thing, then help isn't coming because it has had more than enough time to get there. A planetary shield isn't a defence against a galactic government so much as defence to allow protect the planet until a galactic military can get there. Same deal for theatre shielded defensive points and anti starship defences. They'll hold off raiders and buy time for relief forces to get there, slowing down and upping the cost of rather than stopping a full scale invasion.

[phongn]

With torpedo spheres, the engineers onboard have to predict the shield openings in order to get a shot off; they can't really predict when the guys on the ground will take potshots.

[Adrian Laguna]

A planetary shield isn't a defence against a galactic government so much as defence to allow protect the planet until a galactic military can get there. Same deal for theatre shielded defensive points and anti starship defences. They'll hold off raiders and buy time for relief forces to get there, slowing down and upping the cost of rather than stopping a full scale invasion.

That's a fair point, and one with real life historical value. Fixed defences have rarely been expected to serve as a means for defeating an attacker, but rather one for delay. At best they've been used to weaken attackers. In the end, it is your own attacking forces that win the war.

The same concept that applies in the real world applies in Star Wars. The shields and ground-to-orbit defenses are not meant to destroy the attacking force, or even hold it at bay indefinitely. They're there so that the planet does not fall while the rest of the armed forces marshal re-enforcements.

[PainRack]

What part of this did you miss?

That is the quick version. In reality, it takes almost a hundred heavy weapons technicians to coordinate the tube launches. The target area rarely exceeds a six meter square. The hole this produces is actually a power surge that only lasts a few microseconds. If the turbolasers have not made their shots in this time, the process must start all over again.

Wow, that sounds like "can shoot through split second opening".

Oh bollocks. Those holes were created by the proton torpedoes exploding against the weak spots. Attacking an area that's going to be created by your weapons fire is entirely different from exploiting a hole opened by an enemy.

Again, if this capability was so widespread, why was it that the K-wings relied on density of fire and luck to destroy the shield generator in Before the Storm?

Wait Wat? Wait WAT?

Luke never fought with TIEs at all. You must have the super seekrit Singapore-only edition of ESB. All Luke does was take off from Hoth and fly straight to Dagobah.

Right. You do know that in the radio, Luke encountered TIEs when he was leaving hoth, right?

Starfighters are extremely expensive to fuel and keep in operating condition. A starfighter requires expensive fuel cells for power. The most efficient fighters drain their power after a few short weeks of standard flying - and the same amount of energy is exerted in just under an hour of combat flight.

Disproven by canon OT as well as the EU, where X-wings had the power to leave Hoth, transit to Dagobah and then enter Cloud City. Not to mention Rogue Squadron where X-wings were in semi-continous combat for hours straight.

Except that the Republic and CIS also have absurd quantities of ships available by the mid-point of the Clone Wars.

So? If the Republic tosses such a fleet at a planet, the CIS would equally toss such a defending fleet at the planet. You're deliberately twisting the point.

The point I made was that the purpose of fixed defences exist solely to tie down enemy forces. If you are overly reliant on space forces for your needs, you're going to tie down highly valuable assets on ground missions.

Assets that could be better used elsewhere, or would become vulnerable to your own space defenders. Therefore, a large ground army is required, solving this problem of tying down space forces.

Actually, If I remember right, the only survivors were in deep core bunkers, e.g. bunkers deep within the planet's crust or mantle. If you have to dig that deep to survive, then that's not an economically feasible fortification.

Yes. And since you're not tossing BDZ levels firepower at the base itself, what's your point? We already do know that SW environmental systems do have the ability to decant such heat levels. The question is only whether bases will come equipped with them. Considering that any defensive position equipped with fixed turbolasers will require these systems just to survive its own turbolasers firing, not to mention the shields......................

[Connor MacLeod]

The Hoth shield was mentioned in the "Inside the Worlds" as a ripped out shield generator from a large crusier(I'll have to check).

IIRC one of the "Tales from" anthologies mentioned that the Hoth Shield Generator also got routed from KDY supplies as well. I think only some of the parts were from the "Praetor class" battlecruiser IIRC.

Either way I don't see how its supposed to be "exceptional".

And don't forget the Endor shield. They coudln't breach that by conventional bombardment either.

As for range. The Venators doing light minutes easily outdoes anything Rebellion has to say on the issue, and more so...a planet's TLs are at a disadvantage by the sheer fact they only have so much sky at their disposal.

At Hoth Vader had wanted to emerge from hyperspace out beyond the asteroid field and then bombard from a distance. The distance they came out at was a "close striking distance"

[Connor MacLeod]

With torpedo spheres, the engineers onboard have to predict the shield openings in order to get a shot off; they can't really predict when the guys on the ground will take potshots.

Pretty much. Torpedo spheres can pull off the "microsecond bombardment" bit because of the lengthy process (which requires extnesive and dedicated sensor arrays) required to locate the shield weak point and the generators. They know beforehand where to aim and fire: its part of the whole proceess (and if they screw up at any stage, they have to begin the lengthy process all over again.)

The Hoth situation (the "split second" bits coming from WEG, the novel, and the radio drama IIRC) is different. They have no way of knowing beforehand WHERE a shield opening will be created (its hard to scan THROUGH shields, especially planetary shields. Which is noted in the Torpedo sphere entry, I might add.) and thus they must react (Which takes longer.) Its quite entirely different from a pre-planned,, coordinated bombardment.

[Connor MacLeod]

as for ground forces, theres a big distinction between taking and holding a planet. IF you're just looking to wipe out forces then you probably could do with a smaller number of better equipped troops (Especially if they have all the heavy firepower like juggernauts and AT-ATs supporting) in conjunction with orbital support. Depending on the target, it would simply be a matter of time and casualties (given enough time they probably could take even a heavily populated planet like Coruscant.)

Holding a planet is much different, and there's no real way shortt of Force-magic mind tricks to really pacify a planet without large numbers of troops.
Especially for planets like Coruscant.

For the most part droids probably make the cheapest and most effective way of garrisoning a planet in need of it (or flushing out enemies from a place like Coruscant.) We do know the Empire seems to have incorporated droid forces in various ways (ie the SD-9 War Droids) into their Army forces in some way. as well as droids in other forms.

[Pablo Sanchez]

Excuse me. Why must the defender be utterly cut off from space reinforcements? Any battle between two galactic powers will mean contested fleets and ground units.

Since we're talking about an invasion with an eye to take and hold a planet, I assumed what was logically necessary to allow that to happen. As with a major amphibious invasion on modern Earth, allowing even any serious contest for control of space during the landing will give him the opportunity to generate mass casualties and defeat the invasion before it has fairly begun.

And the inverse applies. Orbital observation of ground forces can be hindered by surface firepower and sensor jamming.

Scanners aren't really necessary. Optical and infra-red scanning don't rely on the Star Wars scanners and, aided by powerful SW computers, could run down any leads necessary. Jamming is why I didn't say any force down to the squad level could be seen and annihilated. Sensors could probably do that in the clear, but optical and infra-red observation of the type in use on modern satellites could pretty easily detect regiment-sized units if they broke cover and moved.

Similarly, dispersed ground forces are relatively easy to conceal.

And, as I said, completely useless for the purpose of affecting a land campaign. Dispersed force is at the mercy of concentrated force.

You're blithely assuming that an invader must have space superority in order to invade a planet. We already noticed from the Clone War era that relief missions by the Republic were conducted in conditions where space forces were still battling.Praestilyn had a naval battle rage in the system between the Confederation and the Republic, denying reinforcement for the Seperatists and firepower for the Republic.

Reading up on it, Praesytlin also apparently included an obdurate refusal on the part of both forces to make full use of orbital bombardment even during the periods when they controlled the system uncontested (as when the volunteer militia was defeated and besieged). This is probably due to their desire to capture the communications array undamaged, or perhaps due to some cultural aversion to overwhelming bombardment.

The fight also manifested as what may be assumed to be a "typical" dramatic style, including boarding engagements in the space battle and a commando raid on the enemy command center in the ground campaign.

It would be easy to blame this sort of thing on unimaginative writers, but in-universe explanation is possible. Conceivably the Star Wars galaxy has a cultural need to effect war in the style of pre-Nagashino Samurai battles, with lightning raids to assassinate commanders and daring charges and counter-charges. I'm working on what should be possible, given the technology level present in Star Wars. More on this at the bottom of the post.

The invasion of Geonosis was conducted where an viable enemy fleet was still present, albeit one mostly consisted of transports and caught by surprise.

Interesting definition of viable.

You assume that dispersed forces will remain immobile, yet, the Rebel Alliance was able to field such guerilla units against the Empire.

Guerrilla forces are incapable of affecting a military campaign in progress, they are only effective as an insurgent force against occupation--and even then can never realistically defeat the occupation force in a strategic sense, they can only make the territory too expensive to maintain control over. I accounted for this in my first post, when I said that the most manpower intensive phase of the operation would be the occupation. In fact, my guess would be that my afore-described "perfect campaign" would end in a brutal counterinsurgency slog like Iraq or the German experience in Yugoslavia.

If a fleet is committed to siege operations against such a well defended world, then the defences has already fulfilled their purpose by tying down an enemy opponent at a single planet, leaving the board open for a stragetic move.

Right you are. Thousands of similar campaigns would be occurring across the galaxy. It is a war, after all.

More importantly, you assume that armies must only face local units on a planet. What about relief missions? Armies deploying to defend a invaded planety not only make the task of invasion more difficult, armies capable of launching such a mission must be more capable, and thus more numerous.

As I said above, logically speaking an aggressive landing (either by the invader or by a relief force) would be suicidal in the presence of even minor contesting naval forces. A single destroyer breaking the naval cordon could exterminate the entire invading force in a single broadside.

Define exceptionally wealthy. Alderaan, Nar Shadaa both had planet encompassing shields. Nar Shadaa shields were weak and poorly maintained, but there is no reason to disbelieve this was due to neglect. Especially since the shields were renovated after the battle itself.

Don't be silly. Nar Shadaa was a city world and the galactic center of smuggling and other illegal activities. Even if most of the population was impoverished, great wealth would be present in a few select hands. Moreover, before the renovation the shields were expected to offer no obstacle whatever to the attacking Imperial Fleet--the strong vessel of which was an elderly Dreadnought.

Alderaan was well known as one of the most important cities in the galaxy.

These aren't good examples for your argument that such defenses are cheap.

Because such scattered forces prevent you from asserting control over a planet. The Republic was forced to station a garrison on Geonosis to deal with such scattered units.

Yes, you are correct in saying that, large forces would be needed to pacify a planet. There is a difference, however, between occupation and pacification. Relatively small forces would be capable of seizing and controlling all the significant strategic objectives (critical cities and fortifications) on a planet, as I elucidated in previous posts. These forces could hole up in their defensive positions, supplied from space and without real regard to what went on outside their fortress walls, until the peace treaty was signed.

Vastly larger forces, on the order of hundreds of millions, would be necessary to completely pacify an Earth-type planet with a hostile population.

And given the highly accurate and effective weapons of SW defences, any spacecraft that attempts to use such firepower would be wiped out.

You have great faith in the power of fixed planetary defenses to completely clear the orbit of a planet of a large and determined attacking fleet, yet I can't remember a single example of this ever happening in the EU. Please clarify your position with reference to some source.

---
Despite the argument, there is a marked lack of campaigning as I define it in the Star Wars universe. One might guess that we're more imaginative or that we're possessed of more arm-chair generalship than the typical EU writer (Traviss, I'm looking at you). As for explanations without appeal to information outside the universe:
There are laws--unbreakable laws--in the Star Wars universe governing land campaigns, which prohibit the widespread use of orbital bombardment except in specific cases
or
There exists some marked cultural aversion to full exploitation of the high ground's firepower advantage.

I would maintain that my idea makes sense from a logical perspective, given the technological capabilities of forces in Star Wars--but it would be dishonest if I didn't concede that apparently nobody in Star Wars has thought of it. I'm open to a reasonable explanation of why not.