I agree with what you said. But I think AS Roma has a better chance even though in the rankings Roma is 1 point behind Atalanta if they win against Fiorentina. After that they will face several matches and the two will meet next month. I think it is a match to determine who will stay in 5th place and get a ticket to the European league next season. Statistically, I prefer AS Roma because after being with De Rossi I see AS Roma as a solid team.
Roma has come a long way with De Rossi, I prefer to see them play in the next Champions League, I think the Europa League is very little for them to participate in, I want to see how they will play under De Rossi in the next Champions League. In the next match of Roma against Atalanta, it will surely determine who's going to stay in the 5th position, the match may end up in a draw.
The competition for the top four in Serie A between As Roma and Bologna is still very fierce and the fight for tickets to Europe is also fierce between As Roma and Atalanta. However, these two teams have a match that is no less important because they both have a match in the semifinals of the Europa League, of course their current focus is the Europa League.
Atalanta itself has the opportunity to win two trophies this season, namely the Europa League and the Italian Cup, of course this will break their concentration. So it's true, as you said, statistically AS Roma still has a chance of getting a ticket to the European League, even the UCL League. However, what is certain is that both Atalanta and AS Roma have a fast path to getting UCL League tickets, namely being able to win the European League trophy.
I agree with you, I think that's the only chance Roma and Atalanta have to get their tickets to participate in the next Champions League. I don't think Roma or Atalanta will qualify for the next Champions League through the Seria A league, since Bologna has already occupied the fourth position and they have been playing very well at this point. Roma needs 5 points to overtake Bologna for the 4th position, I don't think that will be possible because I believe Bologna is not going to lose 4 points in their remaining games. Roma needs to play in their best form to defeat Bayer Leverkusen to advance to the final round, if they perform weakly they will lose, we know how strong Leverkusen has been playing this season, without losing any of their games.