Manchester United's manager has no choice, he will need to sell many current players to sign new players and create a team that reflects his wishes. Keeping Højlund in the team would be a big mistake, just look at his performance;
Højlund = 24 games, 3 goals, 0 assists
With this excellent performance, it is better to sell him for a price that is at least 50% higher than what Manchester United spent on him, and then buy Osimhen or Viktor Gyökeres who is at Sporting and it was Ruben Amorin who brought him, so it would be easier to bring him to Manchester United. Regarding Rashford, they will probably sell him to Aston Villa, that would be a better option
It's better to sign Osimhen than Gyokeres, Gyokeres rarely score against big teams like Dortmund, Porto, and Club Brugge. Osimhen already proven to score against big teams, it will not be wasteful to sign Osimhen rather than trying to gamble with Gyokeres.
I still can't think why Manchester United want to sign Hojlund for such fees when they don't have a reliable striker, they should sign Hojlund with a purpose to be substitute player instead of main player.