I'm not sure if Ime knows about this obscure NBA rule. The Grizz and The Spurs both played 10 each in a close game.
It comes down to his circle of trust. He has a group of 8 or 9 people that he trusts to execute the game plan he wants and play the scheme he wants. He's shown all season that he doesn't believe in throwing in some guy for 2 mins here, someone else for 5 mins there. If he feels he needs to he will just increase or decrease the minutes within that circle of trust accordingly. E.g. GWill and White were playing 20 mins with Timelord there, now he's not they're both playing 25-30min and Pritchard gets more. He doesn't dig into those end of bench players - probably because we as fans rate them much higher than he does

If he is forced to play someone else because of injury he will give them a lot of minutes (e.g. Nesmith being glued to the bench than playing 40 mins vs Toronto), rather than splitting those minutes among 3 people like Brad used to. Brad used to toss 3 mins to this guy, 2 min to that guy, just to break up the monotony of the rotation. But he also let the players freestyle a lot more. Ime is a lot more structured, he wants them to play a specific way and I think he feels the less 5 man permutations he puts out on the court the more control he has over that.
The big risk is obviously if someone gets injured and you have to rely on the scrubs...but that's not just an "us" problem, I think any team that loses 2 key rotation players would be in a difficult position. Right now he's delivered the results over the past couple of months as the team has gone on a tear, but a couple of losses and it's natural for fan doubts to come up...that's why we are called fanatics after all

If he manages to go on a deep playoff run with his ideas, then that will be some kind of vindication, but if the team is perceived to have underachieved all the knives will come back out. Which is the way it is with professional sports and I'm sure he understands that. You're only as good as your last game.