You may think of the following as stupid, if so, please keep it to yourself or PM your outrage to me.
I just thought of something a little bit ago. Polygon swapping is possible, and so is model swapping. Then it hit me that I have seen nothing of the idea of bone tree swappping discussed here.
I don't know much about bone trees, other than they have hierarchies, and that we can manipulate them to some extent. However, I thought about some of the problems with Zero, and thought this could be a possible solution for some of them if it could be worked out.
In my personal opinion, using Zero's original bone tree is foolhardy, as he has no bone on his Z-Saber hilt, and it makes you wonder about it. I think most of Zero's animations in TvC do not even actually have him holding the hilt in his hand while he attacks, other than Dark Hold, and even then we don't know exactly how that is done, we also do not know how they animated his hands for moves like Sougenmuu, as he has no apparent finger bones to speak of.
So the solution I think is a Model AND Bone Tree swap.
Here is what I am thinking.
By putting Zero's TvC model over Ike, then the bone tree and model over to Link's file, the problem with having enough articles would be solved, Plus, this means we have Sword Bones we can work with, meaning we can figure out how to make Zero sheathe and unsheathe his Z-Saber at will via Animation and PSA.
Problems I see: The swapping of whole Bone Trees is mainly new ground I think, meaning there may be unforeseen hazards along the way. Various glitches and errors can occur, and there is the possibility it may not work at all, then there is also the problem with File Size, we would need to figure out a way to keep the .pac file from exceeding the limit of Link's.pac, or whoever else we could decide to put him over, or the idea is scrap.
By doing this, I think we would have more range of freedom with Zero if we can get it to work, we could even make the Z-Saber leave his hand if we so wished.
Though this is currently all just hypothesizing.