Giving it some thought (largely because I am bored):

Savai: Savai's Red/White/Black "factions" manifest the combination differently. Snapdax is effectively a serial killer, combining White's sense of justice with Black and Red's sadism; the same likely applies to most other cats. Drannith is completely opposite to the Mardu in being a highly pragmatic society where nothing goes to waste, where class inequality does exist and where constant research and even philosophical pursuits occur. It is in a way a stereotypical fascist nation, mostly White/Black but with hints of Red in its application of violence and few artistic pursuits.

Ketria: Ketria's Green/Blue/Red factions seem to be more united, largely because human populations are mostly composed of small settlements. Illuna craves perfection (Blue) through using cosmic harmony (Green) and the imagination of dreams (Red), and human worshippers likely seek the same through pilgrimages to see it. Most elementals have different agendas or none at all.

Indatha: Like in Savai, the monster and human factions are well seperated. For the nightmares, White/Black/Green means using the light to conceal the darkness, and maybe spice up death magic as with Nethroi, making them a bit closer to Sultai's idea of ruthlessness and Dimir's idea of deception than to Abzan's endurance. For Skysail, White and Green are represented by their sense of community and peacefulness, while the Black is likely manifesting through their desire for independence, again pretty opposite to the Abzan. Notably there are several Skysail zoologist quotes on Black and Green cards, suggesting a Black/Green fascination with these creatures.

Raugrin: Dinosaurs are dinosaurs. There might be something more to Vadrok, what with the town incident, but otherwise it is just a raging not-dragon that can fly and shoot holy fire. Lavabrink, by contrast, is a thriving city that combines artistry with progress, using lava as a technology to construct beautiful cannals, waste disposal and all manner of artifacts. Close enough to the Jeskai, though far more physical than spiritual.

Zagoth: The beasts, much like the nightmares and the cats, do show this wedge's philosophy. They're herbivores that are typically peaceful, but have a long picture perspective of things and are willing to get ruthless. Brokkos in particular fits the "neutral" Black/Green/Blue archetype speculated but not seen until now, someone who isn't really concerned with petty thinks like an attempt on his life and even offers his own perspective of the past and future to help humanity for probably some unspecified agenda. The hunters, by contrast, are simple exploiters of wildlife, just less whimpy than the Sultai.