well with the event of xbox controller support plugin i suppose you could make it where you need controller and id those controller so that you could have one function with each different parameter calling out which controller ID ?
I dont have the tools to test it with. But I wonder if it possible to put each player controller id into the game code and have it done by a single movement function with parameter so that its being use by the correct movement but like what others have said you may need mirrior events for them.
Although it would be cool if say a zelda coop through a mobile app and you had a host device to project the game onto the mobile phone so that all its doing is sending and receiving packet to play the game. theory wishful thinking. but id think that would just drain the phone too fast.