IMO, this limits Harper’s effectiveness. He has less time with the ball in his hands this way. I think they should stagger those minutes until Fox leaves. You’re basically taking away the team advantage that the Spurs would otherwise have with 48 minutes of deadly PG play.
There has to be a fair bit of overlap to get both Fox and Harper the minutes they deserve and to keep them content.
Easier to control it if Harper comes off the bench obviously, but either way it will happen.