Forgive me if this is already possible, but I don't believe it is.
Concise description:
Objective based maps can be won by the team, not just a player.
Specifics:
Objective based maps can be won by the team, not just a player. For example, Peloponnesian War requires the shields to gain victory and instead of one player having to secure all the shields in a team game, if the team secures all the shields then they achieve victory.
This will improve the following aspects of the site:
Make objective based maps more interesting in team games.
It will add a different level of strategy to some of the maps.
It will make team games more interesting.
It will introduce a stronger concept of allies and team goal setting to games.
It will probably be fun.