Actually there is nothing wrong if we say Man United is one of the worthy candidates to hold the UEL title and I agree with you that we all do not know what Amorim is planning. Because it makes sense that in the EPL maybe MU lost against Arsenal but in the UEL we have seen good improvements and can have a big influence on MU to continue fighting until the final round later.
I also agree that actually Amorim only needs a little improvement in the defense line and in january Amorim chance to try to fix these weaknesses.
Of course there is nothing wrong but we also need to see the opportunities and support to predict the strength of one of the teams that want to compete for the title. Manchester United is indeed much better now but we see that there are still many things that need to be done by Amorim, in the Premier League they lost to Arsenal so there are still many things that need to be fixed or improved. For this season Manchester United is still trying to build team performance and I have not seen their chances for the title competition will be more open, but anything can happen if Amorim can change Manchester United to be better in a short time.