A mission concept using the proposed functionality, imagine this being played by around five people:
A mission where the whole map is contested with enemy AI forces and the players are commisioned officers in some invading army all under the command of a general (the zeus player). The players must use their starting forces to do a naval landing, after which the zeus will assign them reinforcements and give them further orders ("Player 1: Take your platoon and hold this town!" etc). Imagine everytime a player platoon takes a town, the Zeus gets resources to call in additional forces or support. Thus begins an interesting mission involving strategy and tactics on a larger scale than what these few players otherwise could have played.