Well we'll see if you have anything better.
I tried.
There is never shown more than 17 Rebel ships on screen at once. 14 X-Wings, and 3 Y-Wings to be exact, so the number is at least 18.
"We count THIRTY Rebel ships Lord Vader" There were thirty.
No more than six are shown in the origional deployment. Vader's and his two wingmen don't count because they never saw action in open space.
I assumed that there's no reason to believe only half a squadron would be launched. I believe it's be stated in the literature that only Vader's personal squadron was launched in the battle.
Fine, there were 10 TIEs dogfighting.
The total fighter count so far is 14 X-Wings to 6 TIE Fighters. On screen we see two TIE Fighters gunned down to only one X-Wing lost. That leaves 13 to 4 remaining. Out of those 13 X-Wings 7 are accounted for, either surviving or dying by other means, leaving at least 6 X-Wings and 4 TIE Fighters whose fates are unknown.
Again, you're ignoring the thirty Rebel ships quote. And assuming that only half a TIE Squadron was launched, which is just plain illogical.
We never see more than 3 Y-Wings on screen at once, so it is possible that were only 4 and none were lost dogfighting with TIEs or shot down by surface guns.
Why call it Gold SQUADRON if there are only 4 ships?
Not necessarily, the lone surviving Y-Wing never made a trench run, and yet it wasn't destroyed beforehand, or at all.
So? It managed to survive the dogfighting, but the TIEs held it up so it never was able to make the trench run.
Once again Vader's kills don't mean jack shit because it wasn't a straight up fight. A Mig-21 could easily gun down an F-22 in similiar circumstances, but that doesn't make it a better fighter. The screen evidence shows a 2-1 X-Wing advantage, and ROTJ shows similiar numbers. Everything else is speculation, your hand waving does not change that fact. Come back when you have something better.
I wasn't using Vader's kills to suggest TIEs were better, I was using it to show that Vader DIDN'T destroy all 30 Rebel Fighters, only 7, so the other 23 were destroyed by other means, and since the Rebels were said to "be able to evade our turbolasers," it suggests that a small force of 10 TIEs (exculding Vader and his wingmen) was able to take out, at the most, 22 Rebel Fighters. Makes the TIEs look superior to me. . .
To suggest that you can take the kill breakdown seen onscreen as valid is utter foolishness. To think that the kills seen onscreen represent an accurate breakdown of the full battle is absurd. There was far more fighting going on than what was showed onscreen.
My speculation is more feasable that you disregarding anything that may have happened offscreen.