I don't want to be too optimistic about the conditions that have occurred at Manchester United this season, because Manchester United is not 100% ready for the arrival of Amorim as a coach, maybe everyone believes that with Manchester United playing as the host, it is impossible for Amorim to achieve his first victory, it is possible that FK Bodø/Glimt will defeat Manchester United at their own home, so I am still pessimistic about this match because this match has not started yet, anything can still happen.
From a bettor's perspective I would rather consider the odds given by the bookmaker which can be used as a reinforcement of who will win the match.
Man United @1.21
draw @7.20
Bodø/Glimt @13The odds difference is very large and that means Man United has an 80% chance of winning and there is no doubt to say that Man United is guaranteed to win.
So your doubts should be better reconsidered even though football is always full of surprises but bookmakers always know what will happen.