I don't think it applies to being great. Charles Barkley was great, Shaq was great and you have to admit that Lebron is and will be remembered that way.
The one thing they don't have is the legendary status that Jordan, bird, magic, Russell and Duncan will have. When you think of the bulls, Jordan comes to mind. The same with the celtics, lakers and spurs. The guys that stay with their original team, and win, will be a legend in those towns. That's something that Lebron will never have.