Some last thoughts include: Man, AT-ATs (or AT-ACTs) ain't shit. I have to put a million rounds into those things in Battlefront and it was intense seeing them being brought to their knees in Empire. But here? Just a few U-Wing rounds to the legs should do it. lol
I thought about this, too, but then I realized that the AT-AT's we see in the climax probably aren't full battle-ready AT-AT's. Many of them visibly missing parts (like the one with the hole in the middle) and this is just the garrison of the planet, they weren't prepared for a battle on the surface. Compare this to Hoth in ESB (and Battlefront, I guess) where we're dealing with a full-on invasion. Of course the Empire would use the best AT-AT's they have for that.