ETH had managed Onana before, and after a year here, he believed that with Onana we can challenge City.
ETH had managed Antony before and he thought he is Man Utd material, unstoppable, worth any price.
ETH had managed Amrabat before and he thought he is a much better option than Fred.
ETH knew Mount well, and he though he is the player we need in the middle, in order to challenge City.
I can think of two reasonable explanations for the above:
1. He has no clue. He doesn't even understand if his own players are good or bad. He watches these players everyday, for years, and he still has no clue. Amazing, but...
2. His manager gives him a cut from the transfers. (I really can't believe this. )
Do you have a better explanation?