(Also I did not know Corsican society could be this complicated)
It's easy to forget just how small this society is. The population of Corsica at this time ITTL is probably close to 150,000 (we're a bit ahead of OTL; Corsica's population in the census of 1786 was 148,172). If that was a city in today's Italy, it wouldn't even crack the top 20.
It's true that Corsican communities are still quite insular owing to geography and (the lack of) infrastructure, but if we're talking about the "ruling class" these people basically all know each other. A lot of them are related. There are only about thirty families in the "upper nobility" (that is, marquesses and counts), and only slightly more families in the "lower nobility" (hereditary knights), which is not dissimilar to OTL - after the conquest, France recognized 70 Corsican families as "noble." Politics are always personal to some degree, but they are intensely personal here given that you could fit basically every person in the kingdom deemed eligible for high office into a modestly sized ballroom. There are "interest groups" in a broad sense - rural notables, urban professionals, inland farmers, and migratory shepherds are identifiable groups with certain shared interests, and I've discussed some of those interests over the course of several updates. But because the political class is small and political organizations almost nonexistent ("parties" are not yet a thing), those interests are often buried by personal conflicts, petty grievances, and narrow self-interest. And as well all know, interpersonal conflicts can get very complicated indeed.