you are right Barcelona and Arsenal are the most likely to win the Europa League title. However, Roma, Union Berlin and Ajax teams should not be neglected. These teams are consistently performing well in their respective leagues. But Barcelona and Arsenal have the strongest squads. Now it is natural that the team that plays consistently well will win the title.
Barcelona's next obstacle in winning the title is Manchester United. It will be very difficult for Barcelona to win against United. Barcelona's performance against Manchester United will tell whether the team deserves to win the title.
For Barcelona vs United, we have discussed it many times. but for other team candidates such as Roma, Union Berlin, Ajax, it is true that this cannot be ignored. in particular, Rome and Ajax. these two teams are playing quite well, but their performance in the last few weeks has not been very impressive. I quite like Roma's game this time, usually Mourinho always uses defensive tactics. but at least, Rome will also provide resistance, especially when they are against Red Bull, which is statistically superior to Matthias Jaissle's squad. Likewise for Ajax, I don't really know this team. but at least, Ajax is tougher than Union Berlin.
But by the way, however, Arsenal is the most ideal candidate in the race for the championship trophy in this competition. Arteta's troop squad is more established in terms of play, performance, teamwork and mentality. I hope Arsenal can win the Europa League trophy.