There is some truth in what you say in terms of the formation and pattern of the game but he played as a 10 or AM in all of Ajax's knockout games when they had that run in the CL. A run that basically got him a Ballon D'Or nomination. He went into ghost mode for Ajax plenty of times too.
Completely different style though. It's not the position that's important.
Ajax won't ever be sitting that deep to defend, and if they did they won't be launching balls forward expecting him to chase after them. They build the ball up in a controlled manner, they'll push teams back into their half where their technique and quick passing starts to show.
Just look at the first half where he linked up nicely with Sancho down the right side, ok it didn't work out but it was probably our best attack of the half.
We've seen he has the ability to finish when in the box, he has great movement and awareness. The issue is getting to that point. United are awful at transitioning from winning the ball back to starting an attack. We only know 1 thing and that's whacking it forward and running.
Did you watch any of PSG v City last night? watching them both play out of a press from the back was majestic. Currently our team could barely ever string 3 passes together.
My point is yes he can play closer to the goal in a team setup to keep the ball, work it like a chessboard towards the opposition. If we wanted somebody to run and counter attack they should have played Lingard instead.
For me, playing him as a 10 in this team is completely pointless. He has to play in CM (and should have instead of Mctominay) until we can learn to keep the ball better and build attacks with more patience he won't ever work well there.