IDK if coaches are over paid but they're working 100+ hours a week maybe 365 and responsible for directing/managing/hiring/firing/recruiting/communications/marketing somewhere in the neighborhood of 150+ people, as well as making sure 105 of those people get good grades and stay out of trouble, AND while making their employer millions of dollars.
If his end goal is to be a head coach of a P5 team one day $880k (which I doubt we would pay) isn't going to be enough to derail the path he is currently on. I'm also really not sure he is worth that much (that cuts me deep to say that as he was one of my favorite coaches we've had).
This article is meaningless because they are basing it off of Dino’s compensation prior to his new contract and comparing to the public schools in ACC whose salary info is current. If you include his new compensation (rumored to be in the ~$4m/year range) that would put him in the top half of ACC coaches.