You laugh, but in the blue sky phase controller sharing was something I wanted to do.Controller sharing was something I wanted to do too!
I also want to do the opposite, allowing multiple controllers to merge and control the same player. This one will probably make it as DLC, since my "infection" game mode needs a similar set up.
It's something I've done a few times before with my brother. (Don't remember what game it was.)
Just not 4 people to 1 controller... It's a bit excessive.