I don't think Manchester United will be treating the Europa League as their second priority as you just said. Manchester United has stepped up their form a bit and is putting in more consistency in its winning, but I will not be fast to say that they will be able to overthrow Manchester city not to talk more of Arsenal who seems unyielding and indomitable this season. For that, man united will be more focused on the Europa League than The EPL. The only problem is that they will still have to defeat Arsenal before they could secure the Europa title. For now, I see Arsenal as man united greatest Rival.
I'm not a Manchester fan, but I like Ten Hag's coaching style more than any previous coach with the exception of Sir Alex Ferguson. Speaking of United, as far as I'm concerned, Erik Ten Hag has never stated that he is aiming for any trophy. Teh Hag came to coach United, to bring Manchester Uniter in a better direction. he only targets victory after victory in each of his matches, both in domestic competition and the Europa League. after all, Ten Hag is a coach who has high integrity and has the ability to bring United on a par with clubs competing in the Champions League.
Ten Hag knew very well that in his first season he would not be able to win a trophy unless United were really lucky. after all, currently Arsenal and Manchester City are more favored in their domestic league competition. for the Europa league, because we don't know the newcomers who will be brought to Old Trafford. So far, we're just guessing. for sure, Barcelona vs United will present a very interesting match for us to watch. for the Gunners, they remain the strongest candidate to win a trophy in this competition with their positive trending performance.