Depends. In some cases it may be how the weapons are concentrated and/or allocated. In the case of Vraks the orbital defences were concentrated around the Base/Fortress and the munitorum stockpiles (which were underground). This simply meant that forces could not come down on top of or close to the facility without severe losses (How that could be worse than a Siege War... I dont know.)mr friendly guy wrote:Forgive my ignorance, but if these planet anti ship defenses are good enough to repel capital ships, how the hell do invaders even land ground troops?
In another example in IA3 and Taros, I believe the defenses were more widely dispersed - they covered more of the planet, but were also more widely scattered (and quite probably less numerous). In that caes they used Space Marines to punch a hole in the defenses and land (although defenses around the main city/starport, IIRc, were still too heavy to allow a direct assault without severe losses.)