I don't like rookies getting best breakthrough.

That's just what rookies do, every rookie who plays a single snap is a "breakthrough"

I'd rather it was given to a player who has maybe disappointed so far and has finally broken through.

Someone like Clowney or Ajayi.

Actually that's a very fair point - Ajayi was very impressive last season. Benefited from a lack of depth in quality at Miami, but can't deny he stepped up!

Clowney wasn't even our best olb, mercilus was better than any player that won an award