Reimer is a very solid LB. Nothing against him, but he shouldn't be on a D where he's the best player on the field. He's too small to hold up in the rigors of the Big Ten, and that forces him to miss a game or 2 during the season. That's not a knock on Reimer, he needs more around him.
Henrich has been decent, but has issues staying healthy and has not progressed since his freshman year. That's a combination of S&C, poor coaching by Ruud, and bad luck.
Koralevic isn't very talented (slow and undersized) and has shown he's a FCS or G5 level talent, Matauga-Clements looks small to me, and Hausmann is being asked to do too much as a true freshman. Ruud has done very poorly recruiting, retaining, and developing the LB's. I don't know why they have continuously gone into the season with 2 or 3 viable LB's, especially when you can expect injuries to happen.