From my personal observation, Schofield is impressive as an edge rusher.
From the "emperor is wearing no clothes" perspective, I personally believe his technique as an edge rusher is much better than Irvin's. Irvin may be a better, quicker athlete, but Schofield's game is noticeably more advanced. At this snapshot in time, I would prefer to see Schofield as an edge rusher over Irvin until Irvin begins to show better technique. Irvin seems to be caught in "no man's" land. They are trying to find a place to use his athleticism, but the truth is, he is being outplayed by other players wherever they put him (ie. Malcom Smith, Cliff Avril). More a testimony to other players stepping up their game than a knock on Irvin. Mark me down as one who believes that this season will determine if Seattle eventually exercises the fifth year extension option on Irvin. Based upon his current play, I don't believe they would. (on second thought, was he drafted/signed before the new contract structure was implemented?). Having said that, he is too much of an athletic freak to easily give up on. They will lend him every opportunity to step up his game.
Due to unforeseen attrition, I would feel very confident with Schofield playing every passing down at Leo. He would hold his own competently. The thing is...the Seahawk defensive scheme is one of a handful of places where Schofield can excel. Leo was built for "Tweeners" or undersized defensive ends. League wide, there isn't a lot of spots available for players like Schofield. For this reason, Seattle will always be "stacked" at the LEO position.
On another note:
The Seahawk defensive philosophy is innovative and brilliant. Normally, undersized defensive linemen would be a huge liability in the run game, but it is more than compensated for by the oversized defensive backfield. Chancellor takes on offensive linemen as well as any linebacker in the league and Thomas is fearless in run support. Maxwell (and before him, Browner) is very competent at sealing the edge and forcing runners back to the middle or outright tackling for loss or no gain. Even Lane has demonstrated similar ability. Running to Sherman's side? Well that is where the "big" defensive end plays. Further, Richard isn't afraid to stick his head in there either. Because of this, Seattle can put lightning quick players (albeit undersized) on the edge, with their hand on the turf. Brilliant!