Summary: I really don't think McClain is a 4-3 inside linebacker. The speed and lateral range just isn't there for me, and I think he would be exposed because he will overpursue gaps. McClain is great for 3-4 teams because he can play inside, but also move over to the outside if needed temporarily. His best fits are at 3-4 inside linebacker and 4-3 strongside linebacker. McClain is a solid prospect who will likely come off the board in the top 20 picks.
Player Comparison: Bart Scott. Scott has great instincts and size, and is a leader at inside linebacker in the 3-4 defense.
I'm sure it's because your "NFL Matches" section is just the usual copy/pasta from other scouting report articles, but I literally spit out my drink reading you suggest Mixon as a fit for the Ravens. Zero chance that happens lol.