the european league has a different atmosphere from the premier league so I don't predict tottenham and man utd who will be the champions of the european league this season, teams from the italian league and also the spanish league have a big chance to shift the dominance that will likely be shown by man utd and tottenham.
sociedad, lazio, roma, will definitely be a big obstacle for man utd and tottenham, all three remain the favorites to win the european league this season apart from man utd and tottenham (just a personal opinion).
Manchester United and Tottenham are big teams, I agree with that. However, they are in good shape, especially Manchester United who are still in a bad situation in my opinion. Tottenham is a team that can put pressure on, but they are unable to raise their level to become a team that can become champions. I can see in the Premier League, their position can hardly be better from season to season.
The Europa League also provides opportunities for teams from other top European leagues, last season alone the team that managed to become champions was a team from Serie A, namely Atalanta. Even though at the beginning they were not the main favorites, but in the Europa League it is difficult to predict because the advantage on paper is not a guarantee for them to win a title.