Of course, it's a good plan to focus on winning Europa for an automatic ticket to the Champions League next season, because it's like Amorim needs more time to understand EPL better. This was the same strategy that ETH used in his first season, but he ended up not being competent to carry on with his duties. Amorim shouldn't fall in the same shoes of ETH.
I don't agree to focusing on one league alone when you can actually win some other trophies at same time just like other team does, it's possible to have multiple focus as winning more than one trophy a season is very possible, you must not win one alone but in reality Manchester United doesn't have what it really takes to get on with trying to win More than a trophy this season, infact if they are able to win the Europa after all of this strives, I will consider it a very good one from them, having it that they have been able to go beyond the limit we had set in them this much. It's true that the only chance Manchester United may have to go to the champions League next season would have to be winning the Europa but I don't know how well they are going to achieve that.
At the moment amorim should think more realistically to focus on the european league rather than the english league this season, indeed winning more than one trophy in a season is a great achievement, but it requires squad depth and also a mature strategy with also a little luck, and for now I think we don't see that at manchester united, Their position in the league at the moment is very bad and even the change of coach not yet brought much change at the moment, compared to the English league obviously their position is still better in the European league and if they can win the European league at least it will be a good achievement at the end of the season.