Which would only serve to prove that he was only able to win with another great player. Which would, in fact, support my argument, not yours.
But, I will grant you this one concession: LeBron James is subjugating himself, and becoming second banana to Dwyane Wade, in order to win championships. If he ends up leaving Miami, and goes somewhere else to become someone else's second banana... then yes, he may end up with more championships than Dwyane Wade. And he will still not be thought of as the greatest.
That is the legacy of LeBron James: he had to go to another guy's team to win. He's not going to Miami as an equal, the way that Garnett and Allen did when they ended up in Boston: he's not on equal footing with Dwyane Wade. And, he's never going to be, as long as they're on the same team. We've already seen that he can't carry a team on his own, and there's no reason to belive that that's going to be any different seven years from now, so he's going to have to go play second fiddle to somebody else to win again.
Now, there's no shame in going to be someone else's sidekick to win a championship, and that's all well and to the good when you're Robert Horry or Horace Grant, but when you're a guy who's been in the conversation for greatest ever, and you go to another guy's team to win, you are permanently, and irrevocably, taken out of that conversation.