The moon idea is good. It adds a character
Also i had an idea:
When the AT-AT fell wee see the rebel soldiers running and one say C'mon!
It will be cool if after the crash some snowtroopers had escaped of the fallen ATAT and heading towards to the rebels.
Just a brief scene. Also the snow speeder to shoot one of them just before it destroy the AT. Just like AOTC when the geonosian fighters killed a clone trooper...
-Angel