Your coaches etc. don't judge a player by his actual attributes at all. It would probably be too complicated for the AI with all the factors and considerations playing part in judging who is better. So it's pointless saying to the Asst.Man "but but, he's a great tackler, why isn't he better?". The Asst.Man doesn't care
AI is also incapable of telling which position a player is best in. Let me give you an example..
I had this supertalented scottis striker (regen) who desperately wanted to move to a bigger club. I retrained him to DC just to punish him before he left for Torino. He spent most of the rest of his career as a central defender despite him having GARBAGE defensive attributes and excellent striker attributes. Muahaha, that taught him a lesson

The AI played him there just because he had DC position (in addition to striker) and had high CA rating.