Royce has the worst PER out of any player that gets reasonable minutes, he isn't the defender people think he is. The fact is, this teams gets completely exploited by every backcourt in the league, and Royce in the lineup really makes no difference in that regard. And what he provides on offense just doesn't move the needle much. He can't shoot off the dribble, has to be wide open to make a 3, and is not a great ball handler or passer. He developed great, and would be fine as a limited bench player, but he just doesn't bring a lot to the table.
That isn't to say he is bad, just very limited, and definitely not starting material.
JC's usage rate is extremely high, Royce's usage rate throughout his career has been extremely low and he doesn't need the ball in his hands or shots to be effective, feels like he'd be a perfect fit next to JC off the bench. Joe on the other hand needs the ball to be effective and needs to play the majority of his minutes with Rudy to utilize his pick and roll skills. It just makes so much sense to start Joe and bring Royce off the bench. I know the argument against it is that we need Royce's defense in the starting lineup but our defense has looked great the last two games without him, probably two of our best defensive games of the season.
It feels pointless to even be discussing this because we all know all know Quin is too stubborn to make the change.