You have more faith than me.
Sirion is too huge and well connected, Eponllyn is the only free thinking realm of that block, there have been innumerable IC reasons for a breakdown of the Nivemus Sirion relationship and it hasn't and probably won't happen, and CValigus gets cut loose, is allowed by Sirions disregard to be attacked and humbled by other members of the continent and still goes back to bat for Sirion again...
There is no counterbalance to Sirion and geographically they constantly make themselves untouchable, I know I am sounding like a hater here, I seriously am not, I just don't think it is healthy for the continent but I can't see it changing by the current standards.