I agree that he was given a particularly hard task with the other cms selected but it was still against a poor team and he was badly at fault for the goal and on many other occasions. Bit harsh to blame him solely but I don't think Rangnick ever saw him as a dm and that performance I'm sure would have solidified that in his mind. I actually don't mind the false 9 idea but I actually think Donny would be much more suited to the role than Bruno. I think Bruno would be better in the midfield 3 so he can play longer passes and push forward into the box. Then you would have Donny able to play short through balls into Bruno and the wingers/inside forwards whether that be Ronaldo, Rashford, Greenwood, Elanga, Sancho, etc, which he's actually good at. Donny is also good at making runs into the box himself and that was basically his main job at Ajax in the 2 seasons before we signed him.
I don't agree with your views on Fred and McTominay. They are absolutely not dms and don't understand how to play the position. They are poor positionally and don't know how to make themselves available to receive the ball. Fred is a ball winner without positional awareness and a limited ability on the ball, whereas McTominay is quite box to box and actually quite good in attacking positions when given space to get forward.