They stand out domestically. In the Bundesliga, Leverkusen has dazzled, exceeding even Bayern Munich. For this season, they seem determined to win both their league and Europe. Since Liverpool dominates the Premier League, I agree that its hard to predict who will win the trophy.
Although Milan, Atalanta, and Roma are charming, I doubt they're consistent. Leverkusen and Liverpool seem at a different level. I agree with your quarter-finalists, but football is unpredictable. While Leverkusen and Liverpool look expected to dominate, the game's charm resides in its ability to surprise.
With good gap in Bundesliga, Leverkusen will be able to focus on Europa League and it's different than Liverpool as the competition in Premier League among Liverpool, Manchester City and Arsenal are very tight.
Atalanta and Roma will belong to Tier-2 of candidates to go far and win Europa League. Roma is a runner up last season but now they no longer have Jose Mourinho and they will have to beat Brighton in Round of 16. That opponent is capable of beating Roma as they can play well against strongest clubs in Premier League.
I agree with you about Leverkusen and Liverpool, both teams are at a higher level than the others
Liverpool are leading the Premier League as well as being one of the greatest traditions in European leagues, and Leverkusen look unbeatable at this stage
And Milan, despite not being at their best, have a lot of tradition in difficult continental championships, so I won't be surprised if they reach the final
Liverpool have very strong and experienced team and their coach is experienced too. Leverkusen are rising and making big surprise in this season and they are strong but lack of experience from their coach can be their weakness in knock out matches. AC Milan looks to be good not only with their tradition in Europe but their coach is experienced too.
I agree to put these clubs as best candidates to win Europa League but don't know will they have to meet each other in quarter finals if they go through round of 16.