I'm not sure of the exact plans for Pantheon regarding number of players per match, but it seems to mostly 2v2s right now. I suggest adding a filter, where you could check your preferences for 2v2, 3v3s, etc and be placed in the appropriate "pool" with others searching for a game at that time.
Also, I think there should definatley be a way to join pantheon games with a teammate. I'd like to be able to join the same game as my brother without waiting until we get randomlay assigned to the same match.