I'm with Clint on the rugby style, and I swear I saw an article somewhere in the last couple of years about OU trying to be on the leading edge of concussion research, and they have those special helmets for practice with sensors all over them, no way you practice with one of those things on your head and don't think about it.
Particularly with the linebackers, arm tackling comes from being out of position, slow to react, and taking bad angles, because you're out of position. And they've been poorly coached for years in my opinion. I've lost track of the times they fly through the hole at 100% speed and run by the play. Scouts have said for years they're overly aggressive and vulnerable to cutbacks. I really like what I've heard from Ruffin about simplifying things and just letting them go play football, without all the staring at the sideline, waiting for last minute play calls, not to mention goofy schemes the players don't believe in anymore.