I generally agree with Bahku, so long as that dominance is done within a team structure. It needs to be one of those "feed KG the ball every time down" or "give it to PP and get out of his way" sort of things; it can't be a guy just taking control on his own.
It's also a fine line; Paul Pierce has won a lot of games by taking over down the stretch, but we've probably lost a few (in previous years) by relying *too* much on Paul Pierce isos. It's important to have a go-to guy, but we also have too much talent on the floor to allow the other players to be wallflowers.
Basically, what we need is for one of our superstars to somehow play like Larry Bird; somebody with the ability to get all his teammates involved, while at the same time being the undeniable man in crunch time and indisputable leader that his teammates look up to on the floor. I'm not sure if any of our "big three" is capable of that, but I agree it's basically one of the aspects of this team that could be better.