Why do you act like it has to be the same guy covering Lebron the entire game? The answer is sometimes Green and sometimes Pierce. Also, occasionally Bass for a handful of possessions per game.
This.
I wouldn't mind seeing PP first, body Lebron up a bit, beat on him (if allowed), and then move Green to him for quickness. Letting PP and Green to keep their legs. And who ever Lebron is guarding you go to them to start the offense or run around for screens.
You notice that Lebron barley guards the go to guy. When Green had it going a true pro would take him to shut him down, but he doesn't want to work on D, so he guards the other guy. PP started to get going, he switched to Green for a bit. This is why I give a little, just a little more respect to Kobe because he will go out and guard the best guy under 6'10".