I started watching this about 24 minutes in. Up to the goal West Ham had nearly all the possession in that time and Manchester United were usually camped in their own box. The United team looks very disjointed. Now they have the quality to turn around and may well do, and as I write they have scored an equaliser through Ronaldo, but over the course of a season it’s hard to see how they don’t get pulled apart tactically a lot.
In the battle between systems and individuals, systems will nearly always win. If you have a gifted individual who doesn’t work, a Messi or Ronaldo, you’d want to make damn sure you have a team and a system which does the work to compensate. And I don’t think Manchester United, or PSG for that matter, have that at all.