To me I had the perfect low end outcome for Castle.
It's Okoro. Nearly the exact same size as Freshman. Very similar "do it all" playstyles. Both poor shooters in college. Both high IQ connectors on offense (though that hasnt really translated for Okoro to the NBA).
Okoro became a better shooter, but he never learned to be a primary player at the NBA level. Never even really tried either. I could see that outcome for Castle. I really dont see Castle never learning how to be a respectable open 3pt shooter. Sure, that will scare some people, but Okoro is still a viable NBA rotation player.
I see Bruce Brown. That's who comes to mind when I see Castle operating inside the paint and making smart plays, I think Brown is overrated on defense, however, and I think Castle will be better.
Okoro is an interesting name. I think Castle has more ball skills. The difference in them as prospects is that Okoro was A+ getting to the basket and finishing/getting fouled. It didn't materialize into anything in the NBA because he's not a good enough ball handler. Castle was not quite as good at the basket in college, but I think he will have more success at the next level.