The Celtics teams that LeBron faced are easily better than those Pacers. It is an entirely different game now, so I don't know how the Celtics would have fared against the Pistons barnball. How would have the Pistons fared playing against the late 00's Celtics in today's NBA, where you can't play barnball? I don't agree that the league was so much better back then as everyone always claims. Now, with more people growing up playing basketball than ever (credit to Jordan, Magic and the rest of the Dream Team), there's somehow less talent. I just don't buy it.
I say LeBron can play all 5, because I've seen it, so it's not ridiculous. He doesnt need to guard every position for an entire series, but if they need him to, he can for lengthy periods of games. I don't know if he could check a point guard like Paul for entire series, though I believe he could, or at least could have. He's shut down Rose when needed. He's offered good D against Howard and Hibbert when needed. He can guard anyone 2-4 without question.
Link? Make sure it's at least close.
Edit: Other players have lifted their teammates, so that was an error on my part. I meant as much as LeBron has.