Trying to imagine what to do with the SD hit by the asteroid:

maybe CGI could be used to make the model slide away from us and the back- end tilt downwards ala the SD hit by the ion cannon (specifically the shot following the initial hit, where the rebel transport flies beside and away from it). Combined with a larger explosion and chunks coming from the tower region could better sell the scene (?).

I would also consider when making the explosion to have the explosion burst towards the rear of the video picture, as the SD is moving forward (ie when a plane explodes in midair, the fireball extends across the sky as the plane [or what's left of it] continues moving forward).