In fact, it would be the right decision, another thing is that it is simply impossible for financial reasons. United (like probably any other club) cannot afford to change the team entirely when changing the coach. Therefore, United are expecting targeted changes that will gradually lead to the team that Amorim wants. As for selling/renting players, I don't think there are many options. Who needs Rashford with his salary? PSG were after him before Ten Hag.
Amorim needs a serious strategy to drive the club forward. What Manchester united is facing now is multidimensional, for instance, Manchester United has an issue with their squad composition. While there's an overload of attacking players, there's equally an issue with a limited defensive which was an issue underlayed by the past administration of Eric Ten Hag, now Amorim needs to fix that in the midst of a limited resources available to him. They must also work on their recruitment process and strategy which is something I believe Amorim have to address in the interim.
Amorim is not a magician but that is what u see many people calling him or seeing him as before even joining Manchester United. Since Manchester United had him in their list to sign, the matches he played in Sporting Lisbon from that period to when he joined Manchester United was very great, and you shouldn’t think of another replacement for Eric Ten Hag asides from him. He is a very important person in the team now as all hope lies on him for the club to get back to winning ways again.
I just feel that the expectations they had for him was too much and for such expectations, fans will want to see immediate results which sometimes it doesn’t immediately reflect when they newly joined a team. Manchester United are one of the best in the world but their inconsistent and long time poor performance in the league really affected them badly. I think he should be given sometime till next year, before concluding on the stance whether he’s the best choice for the team or not.