I have been playing for 5 years, and the dominance of the Cagilan bloc has been status quo for that entire time. When the island was younger, I'm sure it was much more fluid. That seems to be how it goes in Battlemaster. Dwilight, as the youngest island, is the most dynamic five years after its opening, but even Dwilight is beginning to show signs of calcification. The outcome of the current war could upset that (which would probably be a good thing, really), but it could just as easily go the other way and serve to further entrench the status quo in the north.
If Atamara gets shaken up in the future I'll gladly admit I was wrong, but I think what you're channeling here is a dynamism that once was (and precedes my time in the game), but no longer exists. (Example: If you think Suville is going to become a serious rival to Tara or the Empire any time soon, I want some of what you're smoking).
That isn't exceptional to Atamara though. Sirion and Perdan have always been big powers in EC. Enweil in Beluterra. Lukon in Colonies. It can make politics harder on a continent but it does not halt war. It does not completely calcify a continent. The Cagilan bloc has always been strong in Atamara, but it has had missteps and its strength has ebbed and flowed. That most recent big war isn't a good thing for them long term. Never before have they stirred up such an unprecedented hornets nest of opposition. Likewise with the change of sides of Darka it has lost one of the realms that everyone used to say would always, always be on Cagil's side in the same way as Talerium or Tara.
There might not always be a dramatic standard-bearing loss of territory that will mark out any difficulties the Sirions, Lukons or Cagils of BattleMaster may be having at any particular moment. But it doesn't mean that continents are static and unchanging. And who's to say that Tara or Talerium won't one day 'pull a Darka'? Or that Cagil won't just pick a fight with one of their allies? This is BattleMaster after all and Atamara's big realms won't hang on to all those many nobles of theirs if they let peace settle in.
Even if the pace and state of things isn't to everyone's taste, I really do think there's still plenty of life in Atamara yet. (And Suville might be low on nobles, but I reckon she has riches enough to do anything she likes. They're deffo going to be a dark horse in the future.)
