If you like tactical analysis and have an Athletic subscription, the link below is for you...
https://www.nytimes.com/athletic/6591402/2025/09/04/manchester-united-wide-combinations-analysis/One of my takeaways is that considering how much Amorim relies on both of his central midfielders to create opportunities, the only obvious reason for Mainoo not to be playing more regularly is his "engine" and ability to marshal the entire pitch. He is much more capable in the build up than Ugarte will ever be (if you don't have a subscription, two of the chance creation examples in the article are heavily reliant on Ugarte)
The other thing is...if you're going to move from a 4-2-3-1 to a 3-4-2-1, then it makes sense you need to ask more from your central midfielders than you otherwise would have because you are subtracting one attacker and adding a center back. So why on earth would you not strengthen the central midfielders on your team in order to strengthen your overall attack? In a 4-2-3-1, you can get away with one who is defensively focused and limited offensively, and one who is the inverse of that. That gives you 4 1/2 attacking players (with some contributions from overlapping fullbacks). In a 3-4-2-1, you need both central midfielders to contribute just to get you to 4 (3 truly attacking and 2 that are .5 as they really need to do both) attacking players (with some contributions from wingbacks).
I'm going to harp on this all season because it's going to absolutely knee cap what this team can do in Amorim's system. Mbeumo and Cunha could end up having perfectly acceptable seasons but United's refusal or inability to address the central midfield is going to be what eventually undoes Amorim this season. They went and strengthened the 2 attacking positions in his system that they had the most talent on the roster, took a high risk option to upgrade a 3rd position (Sesko) and then completely ignored the other two positions. They could have gotten so much more mileage out of just adding Mbeumo (as an example) and then getting an upgrade in central midfield.
If/when Amorim doesn't make it to the end of the season, it will at least partially be because United's transfer strategy didn't allocate their money wisely from a roster perspective.