The numbers don't support your claim that Matthews has performed on a level with the players I mentioned though.
You should know that numbers alone do not measure a player's value. Particularly, you seem to favor sacks as the measure of a linebacker. How many sacks did Derrick Brooks have?
Davis was dominant for his first four seasons in the league being named first team All-Pro three times though. In addition his numbers in the playoffs are insane.
Davis also played a position where success very much rides on the performance of the OL and Denver had a monster run-blocking OL in front of him. He had a lot of help to do what he did.
How much help did CM3 have? In his first 4 seasons he had 42.5 sacks, and most of that time he was facing consistent double teams because he was the only real pass rusher we had. And his impact went far beyond his sack total. He was generally disruptive in the backfield player after play whether he got all the way home or not.
But since you're a numbers only guy, let's talk about Pat Swilling since he is the best comparison as far as position, size, athleticism and the manner in which he was utilized on defense. You said that he should be in the HoF long before CM3 gets a shot. Swilling averaged 0.59 sacks per game. CM3 has 0.63 sacks per game. Swilling averaged 2.53 tackles per game. Pretty damn comparable. And I bet you anything Clay's numbers will only improve under Pettine.