Ajax and Galatasaray may be the dark horses in this competition, they must be watched out for because they can give a surprise at any time. It's a bit difficult to make a choice this time, but based on their performance so far, Lazio are very likely to be one of the finalists. Tottenham and MU have yet to maintain their consistent performance, but Athletic Club is still far from expectations, especially as they have just lost to Barcelona in the Super Cup.
Based on the conditions that have been seen from the several teams you mentioned, it is indeed quite reasonable to be wary of Ajax and Galatasaray in this competition, because even though there is still a possibility for several of these teams to get better changes in the rest of this season, Ajax and Galatasaray are two teams that do have more surprising tactics so teams like Lazio and several others should not underestimate Ajax and Galatasaray in the Europa League this season.
Compared to Galatasaray and Ajax, it seems that the ones to watch out for are Eintracht Frankfurt and maybe Anderlecht. Because, so far Anderlecht are also unbeaten and of course, that is an impressive result for a team like Anderlecht who were previously not considered to be candidates for the title. Also, there is still Lyon who certainly cannot be underestimated at all and likewise, of course they must keep up their performance to stay good because if not, the teams you mentioned also still have a chance to fail in the Europa League this season.The competition will still be interesting even though some of the seeded teams have not had good results so far, but there are still other teams who might be able to make a surprise like Anderlecht, maybe.
But there is Bilbao and some other teams that have played very well and of course Lazio despite the few games that they lost recently, but I think especially those Italian teams are not to be neglected in these competitions.
I think the field of possible favorites is still wide open. Sometimes these competitions develop against all expectations and it happened a couple of times in the last few years.
There are still some great names in there, but this doesn't mean anything. I think a surprise could be possible as well. Before the Europa League started, I think Anderlecht wasn't said to be ranked as highly as they are now.