Ian RoyalSouthbank Old Boy I've never seen Henry win much in the air when I've seen him play. That doesn't mean he's no good in the air, just that he's not really in a position where you end up challenging for much in the air.
Height doesn't mean you can compete well in the air either. Strength, timing and courage are very important too and from the look of Kebe I really can't see him being too much use defending set pieces!
Indeed, for example Crouch and Asaba. Both might as well not have/had heads.
Plus Nicky Shorey, who is superb in the air for his size - his timing on when to jump to win the ball is absolutely phenomenal. He had to learn this skill or he'd never have made it in the game, whereas because Crouch has always been tall he's never actually had to learn to jump.