Sharing controls to make play easier surely dates back to the earliest of video games.
My first memory of this is in sharing a free credit left on an Atari Asteroids machine between a group of kids. We pennyless youth cramped up around the machine to share the 5 buttons and precious game. It didn't last long.
By 1980 Atari VCS owners had a less constricted shared play option. The seminal Space Invaders game cartridge featured two player partnership options (games 97-112). Here the controls were split between joystick 1 to move, and joystick 2 to fire. An early form of video game co-piloting.
For many physically and learning disabled people, modified controllers and this type of shared play method will always be an essential way to play.
Room 14 Exhibits