I did a mock up of what the shot of Veer's Walker being in the only one left might look like:

Used the shot of the tripped walker just before it gets blown up, the last frame of Luke's exploded walker, and Vaderios' matte at about the angle that it should be.

Vaderios has pointed out the turret facing the wrong way before and ImperialFighter has pointed out that the sun is behind the rebels in most of the other shots. I don't think anyone has pointed out that there is a guy on a turret on frame right facing AWAY from the walker, confirming the oddity of this shot. Were the Rebels supposed to charge the walkers at some point? Beats me.