Are you positive Horvath was only promised 10? His work ethic loss is pretty severe for someone who exceeded his promised minutes.
In general, I try to get the starts early, and save benching for tough conference games late in the season, when necessary, if it’s a guy I really don’t want to risk. Most players are fine staying above ~85% of your promises, but a small number seem to really want to hold you to every little bit, at least early in the season. So any benching for promised starters, and any dip below the promised minute mark has potential to trigger an unhappy response at one of the check-in points for those players. When you get that unhappy email, if you want to be sure to keep the player, you want to keep them above their request until they get you a happy email. If you don’t get the happy email, they are probably going to leave, from what I understand (this is for freshmen and other first-year players who are upset about broken promises; other players don’t seem to leave in 3.0, no matter how mad you make them).