Hello.
I am currently unsure about how your conceptual thought processes are delving as far as PvP is headed, but when we were attempting PvP the other day there weren't many individuals who wanted to do PvP and so we started to do 2v2 and 3v3 setups.
The difficulty we ran into was when some others would join a game whcih held more than what we wanted and the other had too few. Perhaps in development could you setup PvP game halls restricting the number of players to 2, 3 or 4 based on how many wish to participate and create 2v2, 3v3 and 4v4 lobbies (or soomething similar) so that others may know how many they are up against, etc?