Now that I have broken the ice in terms of me posting, let me offer a list of suggestions:
Set rank limits in who can join your game – when you create a game you can set a minimum or maximum rank for who can join
Increasing game limits based on rank – New Recruits can play 3 games and every rank level increase you can play one more (Privet=4 / Sergeant=5 / etc.)
Game MVP’s – everyone in the game votes for the best player (not necessarily the one that wins; could be for moving fast, being helpful, etc.) which can be another ranking component in helping people know who to play with (could also have LVP [least valuable player])
Mixed team games – For those feeling confident, have the option of uneven teams. In other world, have 2v1v1 or 3v2v1 or 2v2v1v1 etc.
Let me know what you think.