I'm skeptical about Zirkzee and/or Tagliafico. I know both players quite well, and I do reckon Zirzkee is a talent. But he's very far from a finished product imo. He might have had a good spell with Bologna, but he's been out of favor at MU playing which to is a red flag. And you don't have to be a world beater to become a starter at this current United squad.
I also dislike the fact he decided to move to MU and the main reason was the 15M commission they would pay his agent. Why opt for such a strange move as a player? I don't think his agent held a gun to his head and forced him to move there.
Tagliafico is a regressing player, for years now, out of favor with Ajax. Let's be honest, someone playing with Lyon at his age seems far from a world beater. He has 'grinta', but it takes more than Grinta to play at Juve.