No. 2 coaches left, and the two more that may leave were brought in with Cut.
Coaching is a profession where you try to move up to that Head Coaching position. RARELY, if ever, is a coach going to be content with an assistant job if they can get paid more in a better job, one that can get them up to the HC at a major program.
Cut always wanted to be a HC again, and at Duke he can pretty much run the program however he wants and give his kids a free 40k a year education.
Trooper was looking to move up, and frankly, he didn't have the experience to go much higher here. He has a chance at more money and responsibility at OK State.