Wild speculating [but it's the season for it]:
Jarrett Grace --- starting middle linebacker and defensive playcaller and get-in-your-face defensive team leader. Grace came to ND as THE Ohio HS All-Star linebacker --- loaded with experience at the position. Diaco immediately saw that he had "the instincts", and called him his first "werewolf". "Grace Knows Middlelinebacking." If he stays healthy, he is the Man. And, "coincidentally", everybody else is suddenly crosstraining... yeh, coincidence.
Notre Dame lines up defensively in the fall: on the field are Redfield and the Cal safety, Luke and Russell. Sebastian is calling the deep backfield re-sets. Redfield, Luke, and Russell can just play. Grace and JSmith walk out there as starting linebackers, but is Joe the other? Probably. The pre-Grace commentary about Onwualu vs Martini may be a thing of the past, or it may be Onwualu and Schmidt. Nyles and Grier probably wait in the wings. ... as would, perhaps, Matthias. On the DLine, out comes Sheldon and Isaac, but does Trumbetti beat out Okwara, and, mindbogglingly, Hayes, Tillery, or Cage beat out Jones? I say Jarron gets a little afraid and ups his efforts and starts, and Andrew and Romeo split time. Grace calls the plays. Sebastian makes the late adjustments deep. The other guys relax and go instinctive animalistic.
We roll. With good luck regarding no DBack injuries and Grace standing tall, we roll all season.
Now, come on, Malik and Everett --- get YOUR unit rolling! You've got studs at every position.