Posted a prior MP idea with respect to losing MP Players taking over an AI's faction if other Players were willing at this post:
However, giving this MP concept more thought, I think it even more important for existing players to have the opportunity to take over the AI's side in a Player vs. AI tactical battle. One of the more tedious (and boring) aspects of MP gaming is watching/waiting for your live opponent to finish a tactical battle against the AI. Examples of this was watching AoWSM tactical battles occur with Player vs AI-- this was a real sleeper (but we MPs allowed as, although the tactical could be auto resolved, there were frequent advantages to playing it out tactically).
On the other hand, if a player were allowed to operate the AI's army tactically against the human opponent, this would be very engaging and increase, IMHO, both gameplay involvement and enjoyment for all players. Although I have not purchase Napolean:TW, I know they implemented such in their tactical battles up to and including an internet search for an opponent that was playing a game at the same time! There is one game mechanic that would have to be addressed: if more than 2 MPs were involved how does the AI get assigned to one or more of these live players? Forces are split? Randomly assign one? Let the initiating player select which live opponent gets to fight? This would have to be resolved.
In summary, I think this would be a very valuable game mechanic to implement to increase MP game enjoyment.