A) People forget: Niang's success was built on his own 'old man game' deal where he had to carve out his skill set since pure athleticism was not his thing. Naz was someone who went after it when he first got to ISU to even get a chance, and Hali playing with other great 19 and under players likely also contributed. Matt Thomas seemed to really flourish more under CSP but maybe that was a confidence thing.
I'm personally a big believer in internalized motivation to make real improvements in all aspects of life, but if you're paid millions, balancing it out as the leader is needed. Seems like CMC is someone who is very good at finding that balance but still building internalized power within the team. That may have been lost a bit in 2019 but it looked like he used it for improving his own approaches. CSP doesn't seem to be able to get out of that.
B) I think some think ISU is a basketball destination when in reality most basketball fans might remember a couple of years when their name was brought up a few times but not much else. With that, the approach likely needs to be unique in some fashion to have success, or there needs to be serious 'buy-in' from the players. I think that's been strong with some and not others, which just doesn't work.