2 inches doesnt equal more than double rebounds. not to mention MJ had a highger vertical and larger hands which also account into getting rebounds. i guess you could say that Rodman was taking rebounds from him, but LeBron has Kevin Love and Tristan who are some of the best rebounders of the past years aswell.
You don't really need a shooting big man. He can do it all besides that
and post up
he grabs boards too
he is all a center needs