The only reason Man United management appointed Amorim to replace Ten Hag was because his performance with Sporting was very satisfactory, the same thing was also done by Man United when they brought in Ten Hag, at that time he was a successful coach with Ajax Amsterdam. It should be underlined that the EPL atmosphere is very different from other leagues, Amorim needs to adapt to the EPL hard and fast style of play. Now Amorim is carrying a big responsibility, he is expected to raise Man United status back to being a respected club like when Alex Ferguson was still in charge. I'm not sure he can do it anytime soon because the competition in the EPL is very competitive.
If Amorim does not show good progress in a short time, maybe his fate will not be much different from Ten Hag and previous MU coaches. There is a lot of hope that Amorim can change MU into a strong team after Ruud van Nistelrooy tried his best in several short MU matches. Amorim has a job to at least improve MU's performance, if not, he might be compared to Ruud van Nistelrooy by fans. It will definitely feel uncomfortable if such a situation occurs in the team.