Management continues to strive to restore Man United's identity to a club that is ready to compete for the championship title, after successfully bringing in Cunha, they have also targeted several other players to be part of their squad next season. Regarding Osimhen, he has become the most desired property of several EPL clubs after showing good performances with Galatasaray.
I am a little pessimistic about Osimhen accepting Man United offer because they will only play in local competitions next season, I prefer him to move to Chelsea because he can continue to hone his talent on the European stage and that is very good for his future.
In terms of choosing which team to go to, it is indeed a bit complicated for Osimhen if there are many teams that are eyeing him from now on, because apart from the factors you mentioned, Osimhen also has to look at a slightly stronger team to make himself develop even more even though he himself already has extraordinary talent. But if Manchester United wants to spend more money to get Osimhen, I think it could also be possible if other teams don't do that to Osimhen. And one more thing is, if Manchester United is trying to improve their team to be better, try replacing some players including the goalkeeper so that the improvement can be truly maximized.