As exciting a player as Hamidou is, his weak outside shooting could really limit his effectiveness if it does not improve a lot. I cannot think of a lot of players who have come through who have dramatically improved their shooting if not pretty good to start with. Kemba from soph to junior year stands out as the major exception. Others?
It's kind of hard to judge what you mean by pretty good to start with? Although you are discussing Diallo, who is likely a one and done, so the data isn't totally useful, players have seen some pretty good improvement after adjusting to Ollies system.
Daniels went from 24% on 50(JC) attempts, to 31% on 68 to 42% on 120.
Napier went from 33% on 141(JC), to 36% on 166(JC), to 40% on 171, to 41% on 215.
Giffey went from 32% on 34(JC), to 43% on 21(JC), to 29% on 34, to 48% on 120.
Boatright went from 38% on 69(JC), to 33% on 129, to 38% on 117, to 41% on 209.
Calhoun went from 32% on 134, to 24% on 79*, to 34% on 76*, to 39% on 72.
Purvis went from from 39% on 78 @ NCSt, to 36% on 150, to 39% on 182.
Hamilton is probably the only example of a major player not to improve when healthy and with multiple years under Ollie. I think a lot of it is shot selection and Ollie/staff instructing the kids on what is a good shot to take but I think they also do a good job of working on confidence and mechanics as shown by the FT shooting numbers, which I don't have time to run.
Marked (JC) next to those years played under Calhoun.
It will be interesting to see if the trend continues with Purvis and Adams this year. I could see both increasing number of attempts and percentages.