This is an attempt to find out if I missed anything about new animations/skeletons implementation.

What I want to do, is make new skeleton - for both horses and infantry - who run at slower speeds then the skeletons they are based on. So I only need 3 or 4 new animations (run, walk, charge, ...), and not replace the whole animation set of the base skeleton.

I've been using 2 tools: Vercingetorix's Animeditor and NNyL's RePacker. But I experienced problems with both.
First of all, some animations (only horse animations I think) were messed up after using AnimEditor. I don't know how exactly this happened, cos I never altered those animations, I only rescaled speeds of other animations. There also didn't seem to be a way to make a new skeleton with only a couple of altered animations: either I had to duplicate the entire animations set of the base skeleton (heavily increasing the filesize every time), or I had no way to alter a few animations without affecting the base skeleton. However with RePacker this can be done: I just add a new animation, duplicate a skeleton and change the animation filename I want to. Problem is that this only worked for a small number of skeletons, a lot of others simply made RePacker crash.

Also, is it possible with the current tools to add an entirely new skeleton & animations for siege weapons, for example: a trebuchet ?