imo the two are basically, they have a different point of history they value, and it shows in how they function. Twilight’s Hammer want the Black Empire to return, Primalists want the reign/war of the Elemental Lords to return. Pre-Titan, Old God Optional. I pretty much view the Incarnates as a microcosm of the entire Primalist organization, nobody was on the same page except that elements are cool and Titans aren’t.
The fact that it was never clarified which pre-Titan point they were supposed to return to is the reason it didn’t last a full lore-year intact compared to the unified central vision of the Twilights. Iridikron and Fyrakk, in two opposite ways, don’t care as long as it’s not Titan, Fyrakk just wants to kill, and Iridikron actively courts any enemy of the Titans he can. Vyranoth is more personal, focused, and nuanced, able to keep a cool head to get the result of no obedience to Titans, freedom for Dragonkind. I figure Raszageth was the only one who could’ve kept them focused on the process, not the result, given how quickly the Incarnates fell apart.
And I take that dynamic, and expand it to the whole Primalist organization. There was not enough effort taken to unify the vision of who they’re meant to be, what their goal is, leaving them disorganized and chaotic like the elementals they idolize, in conflict against each other within months of the war starting.
The Twilights, were carefully planned, organized, centralized around a single unifying vision of what the future was meant to be, to the point that they seem to still have intact cells of agents even after every leader was slaughtered. To still be able to function as a single organization, despite all our victories against them. Because the Old Gods actually know how to plan.
The Incarnates come off as having blindly stumbled into a rebellion, they never, at any point, knew how to rule, how to make a stable organization, and Vyranoth only managed some level of success by blending her ideals with the Aspects she never wanted to fight. And the Primalists, chaotic, ten organizations in a trenchcoat, attempting to embody the elemental lords they implicitly idolize, tore each other apart as a result.