Caporegime
Not convinced he has improved players 10 fold. Fernandes has improved the team massively because he is picking passes and transitions which is something we were sorely missing. He doesn't try to hold off a man and beat him 3 times before making a pass like Pogba.
AWB doesn't come off as the brightest of buttons does he.
You mention Fernandes and there is no doubt he has almost had a Cantona effect on United but yesterday's goal was set up by Pogba to Rashford then AWB assist and Pogba was far more influential last night with his passing.
What I do say is that Fernandes brings leadership and raises players around him in a similar way to Keane, Viera etc.
Also all the top teams have that one player that they cannot do without. City without Aguero/Kevin, Liverpool without VVD, Salah and Mane etc.