I think all the best Managers have missed one or two top players.Salah and De Bruyne didn't exactly fail, Mourinho said De Bruyne was to lightweight for the League, that's why he headed to Germany.
Salah was just Chelsea being Chelsea..
De Bruyne was always obvious to see his quality, expect Jose has been eating his words since..
Even the great Ancelloti said no to Roberto Baggio many moons ago.
Klopp missed one as well but I can’t remember who.