The whole thing makes no sense for the fact that the scions are politically untouchable. After the sheer number of primals that we've killed, no one would dare turn on you, especially grunt-level soldiers who would only need a gentle reminder that the next time ifrit shows up, it'll be them who have to fight and most definitely die. It'd be pretty straightforward for any one of the scions to make that threat and it'd be a chance to make some of the more useless ones like Minfilia do something useful for once. Given that we aren't held captive in the end, the first plan to come to mind to overthrow the monetarists is simply wait for the next summoning of ifrit and use it to force them to kneel. "Oh, what a shame that ifrit was summoned, sure wish I could help but the monetarists have made up charges of treason against me, I can't go back to Thanalan even if I wanted." You'd better believe there would be blood if the smallfolk were conveniently notified that they were being needlessly sacrificed.

Given the remarkable frequency of primal summonings since 2.0 it would be insane for any city state to not give you their full backing in all circumstances, unless if they like risking an Achilles in his tent the next time one shows up. At this point, I wish I could help a beast tribe summon one and use it as blackmail. God help them if the scions/WoL run interference with their defensive efforts.