It's not only Haaland will perform better than Hojlund, but Hojlund is currently injured, Manchester United would be forced to let Rashford become a striker, unfortunately Rashford is a bad striker. So it's a clear win for Manchester City, even Manchester United has a full squad, the chance to win is still low.
At least Manchester United should prevent to be humiliated
If Man United still want to enter the Europa League then at least they can get just 1 point. But in recent years I have always been pessimistic about Man United. Man United's game dominance is always inferior to Man City. The possession of the ball and the final result prove that Man City is very dominant. Man United currently seems to lose strength when facing big clubs. Poor handling, poor play, no confidence and no fighting spirit. So I think Man United will lose.