This idea is something I have been kicking around for a while, and that I have posted before, but I figured I would give it its own little posting here.
It is something that could be implemented as a proper MM system with proper balancing.

-Teams should always enter and leave the match making system through a pre-loading screen

-A team should be placed in the pre-match load screen after and before each match.

-Each person selects their hero. (NO DUPLICATE HEROES ALLOWED)

-Once everyone has readied up, the matchmaking starts. (By selecting the hero pre-matchmaking the system can look at each players selected hero level, and skill base rating with that particular hero)

-The matchmaking system then places the group with a similar skill level opponent.

-When match is done, players go back to pre-matchmaking screen. Select their hero, and go again. Different opponents, and if someone leaves, different team mates.