Sorry, no comparison.
If Dr Frankenstein were around and we did a simple experiment... we put Bird's brain (no, not bird brain) into LBJ's body and vice versa, what would happen?
Here's what, LBJ (in Bird's body) would be slow, not able to beat his man off the dribble; he'll instead, need to come off screens, and be a normal jump shooter type of player. In other words, his true abilities are clearly earmarked by his athletic frame, otherwise, he's a normal above average to excellent player, at this point in time. He'd still be a good passer and a good teammate but we won't be hearing about him in the press.
Bird (in LBJ's body) would be a basketball terror. Yes, he'd be Frankenstein's monster, not a normal player. In other words, given the various crews of the Cavs, Bird could do any number of moves:
1) Drive, draw contact, hit 2 free throws (90% FT). He can do this all the time, without changing game plans.
2) Beat any opponent off the dribble, including Michael Cooper and Moncrief, the best perimeter defenders in the league. Today's defenders have nothing on him.
3) See 2), thus every possession will force a double team and Bird/LBJ will find the open man w/o needing to see him in transition, thus will be impossible to predict for the opposing teams' coaching staff. Any particular Cav will be open at any given point in time.
4) Finally, if opponents tightly guard the interior and prevent all penetrations, with a Mason-like vise, Bird/LBJ will back out onto the three pt line and drill 'em w/o contest. He can do this even if the rest of the Cavs are cold.
Thus, we're looking at a player who can average ~35 ppg, ~15 rpg, ~8 apg, ~4 spg, when he gets his team involved.
If he goes it solo: ~50 ppg, ~18 rpg, ~2 apg, ~4 spg. Yes, he could nearly singlehandedly win a title by himself.