It's very much possible within a unit. Run a play. Whistle is blown, then run it again, whistle is blown, then run it again, whistle is blown,..........then run it in the opposite direction (that's keep the defense paying attention), then repeat. What I like more about NU, than when I played at Baylor is the fact they "bring the film to the field" in Lincoln. At Baylor were were to take mental notes of mistakes, and such things in the film room, then adjust during our drills/live ball/etc during practice, while our coaches were off to the side barking certain adjustments they want to see, after we have made the mistake. At NU, you'll see Coach Joe in the thick of it barking the same things he probably said in the film room (never been in film room with the team obviously...
). He'll yell out to C.Evans "What do you see?" Evans has to one be able to, ONE, identify, and then adjust all while answering answering Coach Joe with the same tone he would call during a game.
Also, the way NU has it's units is much more insightful than what I had at Baylor. For example, at Baylor, if I'm a starting 5 year Sr., most like the only interaction I'll have with a true freshman walk-on, on the scout team may be during a scrimmage while preparing for an opponent. At NU, you often see drills that bring the 5th year Sr. should to shoulder with a Fr. walk-on during drills and maybe even during a scrimmage (in spring camp). I think that pays in the big picture like seeing what our O-Line went through this season. Drop offs don't always say that one mans talent is greater than the man behind him, it's the comfort and trust you have with the man next to you and him to you.
Anyway, got off track a bit........back to your question, yes, having a unit run some repeatedly is a strong and smart thing to do. You want plays to develop "muscle memory" with the players. The first time it's ran should be as strong and fast as the 10th time it's ran because regardless of the fatigue, it "BETTER" be easier because your are thinking less and just acting.