What I discovered, for this one group only, the manager and their supervisor had essentially created a system for hiring people that could be fired when the manager's effectiveness was under scrutiny. It was very Machiavellian but it was also pretty effective for them. I carefully backed out of the discussions to avoid any hurt feelings, and watched as two more people were hired into the role and then left later on. The manager and their supervisor will still there the last time I checked (about a year ago).
I suggested to their recruiter that it would be useful them to understand all of the behaviors that would allow someone to be successful in their culture rather than just the one they were shooting for. This observation was not unlike Jeff Goldbloom's observation in Jurassic park to have the system count 'all' the dinosaurs, not just stop at the expected number. You can build a system to encourage excellence and that is good, but also check to see if it can be exploited by folks who can fool the sensors into thinking they are excellent. And then put in safeguards to detect those too. I'm sure if they did some data science on roles that turned over a lot it would identify bad managers that were avoiding scrutiny.