BlueCardinal said:

I don't know, it kind of makes sense to not have any Imperial ground troops in this battle. The Empire has these huge walkers that are almost impossible to take down, so just let them stomp their way in and take out the shield generator so that Vader & Co. can land. Why risking losing men at this phase of the battle?

You are right, it does make sense for the walkers to do the heavy lifting, and they did just that for majority of the battle.

But then there comes a time towards the end of battle when troops must be utilized for the final sweep at the dig-ins and within the base itself (something the walkers cannot do as easily), so that's when Veers says: "All troops will disembark for ground assault."

As much as I'd love to see Imperial troops cascading down an AT-AT and charging/shooting towards the dig-ins, I cannot see any place for adding any of that in existing footage, unless a couple new clips were to be seamlessly inserted (which Ady will not do).

So without it looking out of place with what's happening on the screen, to me it's a good decision that Ady isn't going to try to squeeze them in the existing footage.