Well... You can't really just ignore the fact that clan players, in general are better players. In a scenario where you have an almost even amount of infantry from both sides, the side with better players will usually always win the battle. Imho the team balance shouldn't be banner, and instead be based on kills achieved in a single round(CS 1.6-style). If you want to practice teamplay, go organize scrims, or have your own clan-server with BB.
Even though I'll have to add that the BB isn't the worst thing. Sometimes you're on the winning side, sometimes you're not. But those times when you're on the side that gets steamrolled 5 maps in a row. Well... It sucks.