I feel this league would be in favor of United because this is their only hope to qualify to UCL if they can win the league. However, when the transfer window will open, Amorim will get some new players to strengthen the team and that should bring more hope for them to go far in this competition.
Amorim should focus more on this league and not EPL but I believe if he can improve the team's performance with the additional players, he can do better in both competitions.
If they are able to come out as champions and that is not easy because the condition of the Manchester United team is not at all consistent and the competition to the final round is not easy if you only rely on the number of players like now. They can use the transfer market to buy some players but it really depends on the club's finances because in the previous transfer market they have spent a lot of money. This is one of the opportunities for Manchester United to qualify for the Champions League but it really depends on their level of struggle to achieve the final result of becoming Europa League champions.