I have a question, how will this work in terms of characters doing close ranged attacks.
For example, if I want my character to run up and punch my opponent in the face, how much of that will I animate?
Will I animate him up to the point where he punches and then hand off the flash and have my opponent animate his character dodging/blocking?
If possible, i think you should consider making the collab a little bit like this flash. Kind of gives us more freedom in our animating, though may take some extra work in terms of scripting.