I've been thinking about that. At first I was thinking rather abstract about it, and was feeling certain it was possible. Now I'm not so sure, but I think it will be something like taking the horse frame and turning it into a chariot first of all, then "hooking" them together with a scheme that makes them check for one another and move in sequence, one right in front of the other. I fear it's a lot of trouble, but as far as I know the only thing which hasn't been done yet is to put a second, alternate horse type slot in the character's inventory. Once that's been done it becomes a lot more possible.