I'd like to make the following suggestion as a more 'team' based team game.
1) Teammates cannot attack each other.
2) Continents owned by a team will provide army bonuses to that team. The army bonus will be provided to the first team player at the start of each round.
I'd be happy to offer my programming skills to implement the above rulings so they work. But what I am interested is for more experienced players to pick holes in the above rulings - or provide feedback.