Of course, Europa League is hard to predict the club that would win the league until the finals. This is why I don't waste my time to come into conclusions on the club that will be the champion this season. Clubs that you hardly put your expectations on might end up winning the league. Let's just watch and see what happens in the long run.
In my opinion, it's almost impossible to predict who'll win the UEFA Europa League competition during the first round of the competition which is the group stage. For instance, Liverpool and Bayer Leverkusen last season were very the best teams in the group stage and were predicted by many as the potential winners but at the end, it was Atalanta who won the the competition. This season, I've vowed to wait till the quarter finals before I can start making a prediction on who is likely to win it ahead of others.
No absolutely no conclusions at this point and I would rather come up with 7-8 teams than just 2 teams that have good chances to win it. As you said United and Tottenham won't do much in the Premier League, I agree, but in these cup setups, there is so much more possible due to elimination. Like Manchester United playing 2-2 in the Premier League against Liverpool away from home. In the Europa League they would now have a home game and everything would be possible. The league can be an indicator, but it has been misleading in the past. I think it was Sevilla in 2021/22? When they played bad in La Liga and won the title and eliminated Manchester United and Arsenal if I recall correctly.
Tottenham Hotspur and Manchester United are the two representatives of the English Premier League in the UEFA Europa League this season and to be honest, I don't think any of them have all it takes to take home the trophy. I don't want to compare any of them with Sevilla who had a poor campaign in the Spanish La Liga the last time they won the Europa League because I don't think the two English clubs possess the mentality of Sevilla.