Get a random 2.20 guy off the street and play him against a 1.80 who has trained professionally for, say, 10 years. You'd be surprised what the results will be.
Actually, the sign of a good rebounder is when he picks up the ball from the floor. It's called boxing out. If you seal your man well enough far enough from the basket, you might be 5'10 and it wouldn't matter.