I find that, with teams that don't play as teams, ie run off separate directions, you have literally no chance at all. Really frustrating. When you have a team that sticks together you can get healed easily while another one or two protects and whatnot. I've had games where I've literally been on my own with about 4 bullets against 4 people. Not ideal. It's usually the higher ranked people who know how to play properly so, like you said, unbalanced teams is stupid.
That said, I've had some brilliant teams in some of the games I've played.