I don't know about triangles, but of course the two-males duality has often been noted, often with one being older:
I actually don't think women were too important in Welles's aesthetic scheme of things; they just don't seem central to the real action, unless Shakespeare provides him with one that is: the strongest females in Welles's ouvre are Lady Macbeth, Cordelia and Desdemona. But other than those, Welles's women seem to be beautiful window-dressing: his films are resolutely male, without being macho. Of course, the dual-male theme even washes over into some of his stonger acting roles, esp. in the 40s. No doubt Callow should have a field day with all of this, but I wonder if it isn't actually always an internal dialogue? ??? Welles's central theme seems to me to be about morality, and the corruption over time of the soul- in particular, the male soul. At any rate, its clearly an obession at some level, crucial to his psyche to be repeated so often and regularily. Which is why ending Ambersons with Fanny and Eugene and not Eugene and George seems so strange; perhaps Welles was constitutionally unable to depict a scene of forgiveness between two males.
Here's a quote from Maurice Bessy:
Welles: "Women block all conversation. That dates from the day they won the right to vote. They should have stayed slaves...Women are stupid; I've known some who are less stupid than others, but they're all stupid."
And Welles on his relationship with Lea Padovani: "During the nine months that I spent with her, I paid for everything that I had ever done to women for twenty years, but in two days I made her pay for what she did to me during those nine months."
Yikes!!! One does not want to imagine just what happened during those two days...maybe he was macho!
And finally, Bessy on Welles: "...like all artists,Welles carries a woman within himself, which makes any normal relationship with a real woman enormously difficult. He himself has said that though he acts and gives with the soul of a man, he registers and receives with the soul of a woman. And he further states that the only good artists are feminine."
And Welles of course said that Shakespeare had an enormously developed feminine side...