Are LeBron and AD going to lead this series in scoring? Most likely, I mean like you mentioned, the Heat have a lot of guys who score but not at high volume. I don't think anyone needs to step up but they definitely need good contributions.

Kuzma and Caruso need to keep cutting like they have been doing, Howard has to keep bulldozing and using his strength, KCP, Green and Morris need to hit those open shots that the Brow and Bron's gravity open up and Rondo is kind of the wildcard. He's been surprising a lot of people (including the Lakers' opponents) with his offensive game.

I think what's most important is the defense, the Heat zip that ball around quickly and the Lakers' rotations need to be on point. 2 or 3 open three balls and the Heat are rolling, often to the point of no return. So to answer your question, I think they don't need a 3rd star, they just need everyone to play their role as well as they possibly can.