Are you sure that you know when Amorim took over from Ten Hag. It was close go the middle of th3 season and that means he hasn't spent up to one season. You should see the weak players that Ten Hag bought which led to his sack. How do you expect a new coach to use such players to achieve a better result. Amorim only focused more on Europa League last season and he almost won the trophy but the same weak players messed it up. I can boldly tell you that currently, United have a game pattern unlike, when Ten Hag was in charge.
Amorim also made many mistakes, he concentrated all his efforts on the Europa League and completely ignored the Premier League games, besides, if he didn’t like the players that Ten Hag bought, then what was wrong with Rashford? In any case, I think Amorim is a weak coach and I don’t believe that Manchester United will be able to show a better game in the new season. And these few transfers will not be enough to change anything significantly, and since there are not so many new transfers, he will have to rely on the players he currently has in the team.
I don't really know how you view it on your own perspective but as I'm concerned I think he make a very good decision by concentrating in only Europa League, he was just trying to strike a balance because he really know what they can do and that is why he need to make that decision. Amorim hasn't spend a whole complete season as a Manchester United coach so I believe it too early to call him a weak coach, I'm not a disputing your fact but at least let's give him more time to test him. As for Marcus Rashford that has left, it really a great loss for the club, but I think Amorim don't like him and that why he let go of him.
When Amorim came to Manchester United things were already rough and it will be very difficult for him to fight for the top in every competition that why he picked Europa League since they were having a good time there. I respected for make that boldly move.