iamweasel said:

Another option would be that the rebel troops would shoot the AT ST walkers. They are smaller and their armor shouldn't be strong as the AT AT (otherwise the armor would be too heavy for an AT ST to carry).

This would be a more logical choice and I agree that their armor would be no where as strong as an AT-AT's.

I do not know if Ady has plans for an AT-ST (or a couple) to get fallen/destroyed, but I really think this is a great idea. THESE should be what the Rebel ground troops and some turrets will focus most of their firepower on... shoot their legs from under them, but not making it look easy (because of course they still have decent armor).