That isn't entirely true, what stopped LeBron was his lack of will to win. One big in the paint won't stop penetration, if the defenders collapse, you can dump in into the big, if they stay he is position for the carom.
We have had at times a glaring lack of post offense. Shaq only will have to play post offense. Shaq has about the same mobility as KP. He is a better offensive game and is a much better passer. No one stays on KP and they can sag off him and help with the drives, they won't be able to do that with Shaq. Shaq also can catch the ball and finish much better than Perkins. Rondo can dish it down low and have a chance of an assist rather than a baubbled pass.
I love KP 's defense. But I think many here are blatant homers if they think his offense is remotely equal to Shaq's. Shaq is also a superb passer, check out some of his assists per year and I think he will pleasantly surprise some peeps with his passing.