Manchester United new coach have really changed a lot because it's clear that the players are showcasing their skills and I see excellent performances from them. Man City have really turned to something else even the underperforming teams are showing their talent when playing against them. Actually, I agree with you that both teams are in the same stage but one is moving in positive direction while the other to the opposite direction. Since man united is recovering we don't expect them with highest performance to defeat any team they faced. The two defeats the faced in their last two matches was never a surprised to me because both teams are in top 5th and it only takes a strong team to secure a slot there.
I can see why Amorim brings out the best in these players, but they are just not good enough to win many games and go up. I mean could he do better than Ten Hag? Of course he can, I assume he will get more points, but that doesn't mean that United will do great, the team is bad and that's why they are going to have difficult time getting wins and rising up the ranks.
I do not see them finishing like top seven or something this season, probably not even eight. So, there is no turning the clock and becoming good again, they just have to accept they suck. With January transfers and summer transfers, maybe next season they could become a better team and that could allow them to have better results as well which would be finally a happy news.