Not blaming the owners first means you know nothing about the club, Erik Ten Hag wasn't backed with the names he wanted for Manchester United, the players he brought in are player's he has worked with one way or the other before Manchester United and he can look back and say, this player can impact in this role.
Ten Hag was given lot of money for transfer and Manchester United agreed to buy many players on request of Ten Hag. It is not like he wasn't backed by the club to develop the squad and train players with his philosophy. I would say he got more support from the club than previous coaches from transfer money to how he was given power to handle star players in the club.
Manchester United scouting team has got to be poor, I believe Erik Ten Hag has already told em what he wants, has be got any better talent? Lots to say but I'll keep it brief.
Manchester United scout team possibly did their job bad enough but Ten Hag is free to request buying his wanted players. He got them but results are still bad and as a coach, he must be realistic that no way all of his requests for transfer will be approved.
Ten Hag picked most of the players personally, including those he knew from back in his previous clubs and I really can't remember another such coach at Manchester City since Alex Ferguson's departure who has been treated so well and trusted by the management.
Even Mourinho it seems couldn't afford to buy players the way he wants.
So the Manchester United management really trusted Ten Hag a lot in terms of transfer policy and did not interfere in the way he treats players and always resolved all conflicts with players in favor of Ten Hag.