There should be a clan playlist and whether you join up with 3, 4, 5 or 6 people in your party the game finder will seek out a match in which join in session in progress is not allowed and the amount of people is equal. In order to join a clan game, all of the people in your party must be registered to your clan on COD elite(dont need premium to play just on Elite). My suggestion is as follows:
Have it say clan matches where you can pick advanced playlist, elite playlist, and such
you can choose what gamemode
Search & Destroy
You can choose to disable noobtubes, rockets, explosives, riot shields...
The game then finds a compatible match in which join session in progess is disabled and if you quit out then its an automatic loss whether disconnected or not. If host is disconnected his clan loses automatically. Win/loss ratio is kept for each clan. Clans get ranking levels that let others know how "Good" their clans are... or aren't. Losses to lower level clans means greater drop in rankings. This will be a test for bragging rights for clans who could care less to deal with the hassles of gamebattles.
Leave comments on what you think maybe we can spark infinity ward/treyarch and make something happen...