Its been a while since I used Blitz3D but I'm sure that the bones and the vertices need to be the same (i.e. same number, assigned to the same bones).
The best way forward is to use a proxy skeleton anyway. That way you can have independent upper and lower body animations. With a straight B3D animated model, you can't do that.
The best way forward is to use a proxy skeleton anyway. That way you can have independent upper and lower body animations. With a straight B3D animated model, you can't do that.