Well, I don't know about the battles annimations but Reunion used to change some annimations files on some world map models. I guess the annimation files in battles aren't so different... He just raise the models though so he didn't change a lot. I don't know how to do it though, but at least I know it's possible... Maybe one day when I will have more time I will try to change some battles annimation to see if it can be better.
Well see you