Yes, the valuable time they spent on improving player interactions, AI squad building/rotation and a functional J-league.... Sorry, couldnt help to be sarcastic there.
I agree that tests will always be flawed in some way of another (and personally I hate holidaying seasons as a test method). I'd like to see someone like evidence based FM have a go at this. But it does all point to the same-ish conclusion, thats a bit of a tell.
It also aligns with my personal experiences (limited as they might be). I honestly dont have another explanation how this guy, with no (supposedly) relevant mental attribute above 10, got twice player of the year in the championship. Oh wait, he jumps high and runs fast....