Can LeBron James really be considered one of the greatest ever?

Even if he openly admits that he isn't capable of beating a team like the Boston Celtics on his own without another superstar player at his side. How can you be the greatest if you not even the greatest on your own team? He called Dwayne Wade the "franchise player" last night. He said he had to leave Cleveland because he couldn't do it on his own. Doesn't that still tarnish his legacy?