If you look at the two that have been played, of course it is predicted that Bayern Munich will be the leader of group A. In my opinion, teams like Manchester United, Galatasaray and FC Copenhagen still have the same big chance of qualifying for the last 16 of the UCL. . My prediction is in group A
1 Bayern Munich
2 Galatasaray
3 Manchester United
4 FC Copenhagen
Galatasaray should not be taken lightly, they managed to beat Man United previously. I'm also not sure that Man United can win the remaining four matches, in fact I'm more inclined to make Man United make more mistakes than Galatasaray.
I agree with your scenario, it is difficult for Manchester United to wipe out the remaining four matches in the UCL group phase, because two matches are a little easier to play and win, namely when they face Copenhagen, the rest United have to face Galatasaray and Bayern Munchen again. At the first meeting, United had already received defeat from both clubs, perhaps the most realistic thing for United was to achieve a draw in these two matches.
If United finish in third place, then Ten Hag will bring his squad to compete in the Europa League. However, it should be noted that Copenhagen is currently still better than United in Group A, they have one point while Manchester United has none.