There will always be anomalies but in general finding these guys that last this late who are worthy of investing such significant resources in to develop are few and far between. If a team is willing to invest the time and money for projects they typically do it with a first round pick.Jokic went 41st, but I'm not sure he was considered a high ceiling guy. That was also a really deep draft. The Draymond Green draft had Khris Middleton go at 39 but that was partly due to injury concerns.
I do wonder how the new CBA will change this trend as a 4-year college player who can play rotation minutes immediately is a great value on a mid/late-1st rookie deal compared to having to pay reserves upwards of $10m to do the same job. As I said above it is a copycat league so when guys like Norman Powell, Malcolm Brogdon, and Josh Richardson have great success as older 4-year college guys it opens eyes to a new way of doing business with the salary cap bloating the cost of acquiring veteran reserves for these teams......spending $2m on a backup role rather than $10-15m for similar production allows those monies to be allocated on higher tier players. I used Alec Peters and Josh Hart as two examples of players who could benefit if GM's adjust quickly to this added value proposition.