To me, it’s all about catering to individual strengths.
Between Castle and Harper, who is the better off ball player? It’s Castle. Who is the better point guard? It’s likely Harper, since from everything I’ve seen, Castle is focused on trying to be a 3-level scorer.
So why would the team play two point guards together in Fox and Harper in the starting line-up? It seems like a waste. I think it would be a situational thing, just like how playing Wemby and Kornet together would be.
I think the team will want Harper to develop by giving him the ball on continuous possessions just like last night. Having it alternate between him and another primary ballhandler like Fox would be a detriment, IMO.
At least when he’s with Castle, Castle’s goal will be to show off the variety of ways he can score.