Melton's name has been thrown around here a lot lately, so I took some time and watched him.
Pros: great lateral quickness. Leverage player, can get under pads.
Cons: Not great length. cannot absorb double teams often enough, probably because he is a bit undersized. In Chicago's scheme, he plays a position that doesn't have a Seattle counterpart.
In end zone views of Chicago's defense, Melton is the easiest guy to find. Low, squatty, and always lined up on the outside shoulder of a guard. Lined up between the tackle and guard, but shading the guard. This is where you find Melton 95% of the time. Also called the 5 technique. Chicago runs an unusual 4-3 look, rarely having anyone lined up over the center, but often having both Briggs and Urlacher shallow, just 3 yards from the center. Melton is quick enough to jump from 5 to the nose the snap and absorb a center/guard block if the play calls for it.
Melton is not a 3rd down pass rush specialist. His sack totals might make you think otherwise, but he is a platoon player. In for a couple of series, out for a series. This also doesn't help him fit for Seattle, as Pete likes to play situational football. He is versatile, having some success against the run. He isn't a chase runners down kind of guy, but does quickly shed guards and laterally intercept the running lane.
So, how has Melton acquired this reputation as a pass rusher, you might wonder? First, lining up at the 3 with Peppers lined up at the 7 or the 5 leads to a lot of one on ones. Put Melton on a plodder in space, and he can quick his way to the QB. Rarely did I see him simply push a guard back.
Also, Chicago runs a ton of line stunts in pass situations. Peppers isn't so fast that he can take the Clemons/Irvin edge route to the QB, and he is strong enough not to need to anyway. Melton often speed rushes the outside shoulder of the guard, taking him wide of the pocket, leaving Peppers an inside move away from a straight line to the QB. This simple stunt is where much of Melton's pass rushing success has been, as the right side of many defenses have struggled to take away Peppers. Another stunt Chicago runs a lot is to have Melton jump from the 5 to the 3 tech at the snap, absorb the guard and center, and leave Peppers singled on the right tackle. Of course, Melton doesn't get any pressure on the pocket this way, but Peppers does.
Our defense is as different from Chicago's 4-3 as two 4-3 defenses can be. We expect the 5 to two gap. He does not have to penetrate and disrupt, just be able to hold his area, even if doubled. In fact, we prefer he be doubled, because now the linebackers are freed up. We usually have a player on the center's shoulder or nose. We do try to free up Clemons/Irvin to be single blocked, but any inside move they make is usually up to them, and not the result of a stunt. Of course, we run some of the same stunts, but not very often. I assume if we had a player like Peppers, we would do that much more. But we don't, we have speed rushers.
In summation, I will be surprised if Seattle pursues Melton. He isn't a long player suited to being an up the middle pass rush specialist or pocket collapser, and he isn't a fit for the mold we currently have for our defensive tackles in our kind of hybrid 4-3.