I support the idea of balancing out teams, With the release of group finder i do not see this a hard thing to implement. Only thing I do not agree with is preventing pre-mades from grouping up because they do not fit this criteria. If players want to stack healers or tanks or dps then imho they should. Even though they can heal other players have the ability to hit hard, interrupt or stun healers. Also in PvP healers are a bit squishy and as you said they do not fit your mold so if there are 4 healers then there are only 4 spots to fill with healers/tanks/dps. Im not huge in PvP, however i had my fair share of playing it. I like the thought and when they release group search i think they should balance teams based on classes however restricting play is a bad idea.