Wait, the AT-ST's are gone... because of "continuity"?
Then again, it's much more fun to speculate where they came from in the first place. See, when a boy AT-AT and a girl AT-AT love each other very much...
We're not going to see how the big walkers got on the planet. We don't see what happened to all the walkers or how the soldiers get from inside them and then into the base. But this part is intolerable?
Just blow it up! Sheesh. :(