Liverpool, City, Spurs, Chelsea, Arsenal (maybe, not sure), all deploy 3 central midfielders who function well together. United have rolled out two so far (Pogba + McTominay). There in lies the 'issue' or expectation of fullbacks.
Liverpool - Fabinho, Henderson, Wiljaldum
City - Rodri, Gundogun, KDB and/or Silva
Spurs - N'dombele, Winks or Sissoko, Eriksen
Chelsea - Kante, Jorginho and/or Barkley, Kovacic or Mount
Arsenal - Torreria, Xhaka, and/or Gunedouzi, Ceballos, Willock
Lingard or whoever plays that position for United is more CAM/SS. And the functionality of United's central midfield isn't as good as the other teams atm. When Traore came on yesterday, it immediately pushed back Shaw and stretched the midfield a little thin providing more space for Wolves and opening the game up for everyone. For years now, the right back for United has served as the outlet more than the left at least since Evra left the club. But then it also coincided with losing CMs like Scholes and then Carrick.