Interesting analysis on the characters in Roma. Given the unconventional approach to plot, I was prepared to think that applying archetypes to the characters might not translate very well, but given what you’ve come up with, I can some relevance here.
I concur that we best understand the story Cleo and Sofía as Protagonists. Clearly, Cleo is P1 so we may think of Sofía as P2. As noted earlier, each has their own arc, but they mirror each other in dealing with horrible treatment by their lovers. It’s tempting to look at both Antonio and Fermin as Nemesis figures who don Attractor masks, but then I suppose one could look at them as Tricksters as well. That said, given how shabbily they treat Cleo and Sofía, I can see them both as Nemesis figures.
I think your analysis of the other characters works, but here’s a question for you: What function does Cleo’s baby play? She did not want the baby. She reveals this truth in the moments after she saves the children from drowning. That is the story’s Final Struggle, per my language, and in the catharsis of saving these youngsters she has grown to love, her psyche is shaken to the point where she can admit this secret she’s been harboring for months.
Is the stillborn child a Nemesis? Trickster? Negative Attractor?
It’s an interesting question and since it does figure to be the most dramatic psychological moment in the movie, well worth considering.