Let's not forget that for all intents and purposes, Desnair is out of the war for good as soon as the Haarahld VIIs arrive in the eastern Gulf of Dohlar in August or September. All Desnairan supplies and troops are currently being shipped to the Salthar canal in Silkiah via Hankey Sound. That's about to come to a screeching halt. (Well, a bubbling, gurgling halt as all the Desnairan shipping descends to Daivy Johnes locker!)
The road up the west coast of North Watch province in Desnair (the isthmus that connects it to Silkiah) is already cut in six places, so shipping troops and supplies north from Desnair is going to be impossible soon, and an army marches on its stomach, which Desnair just learned the hard way. So there won't be many Desnairans involved in fighting for the rest of the war.
Ditto for South Harchong, which is about to lose its main harbors and a goodly amount of its shipping. With the ICN running wild in the Gulf of Dohlar on a permanent basis, all the countries on the southern side of the Gulf of Dohlar are out of the war. A large amount of the supplies and troops for the war have been moving by ship from North Harchong and the border states as well, and that's going to end by next year. (And quite possibly earlier if the ICA manages to seize the Salthar canal through Silkiah so the ICN fleet in the Gulf of Dohlar can be easily resupplied and several river ironclads can slip through.)
What we're about to see is the destruction of Kaitswyrth, Wyrshym, and the Harchongese horde. Dohlar will be suing for terms when it faces invasion. Some of the border states may as well.
Clyntahn will lash out like the rabid dog he is, seeking scapegoats and making examples of anyone he deems lacks sufficient zeal or shows defeatism, which may be what we have seen in the sneak snippet about Thirsk. The Inquisition, which isn't exactly beloved at the best of times, is going to make enemies across the globe with its excesses until entire countries tire of it. I expect a lot of army units will eventually shoot the inquisitors assigned to them rather than stand and die under the heretic's guns.
I suspect Cayleb will make an exception of taking prisoners when freeing a prison camp, which may happen in HFQ. HM isn't terribly far from some of the camps in Cliff Peak, and Kaitswyrth is the worst of the CoGA's generals and the most likely to take "guidance" from Clyntahn. Unless BGV destroys Wyrshym this winter, Kaitswyrth is the most likely to beat a hasty retreat soon, leaving prison camps in his wake.
Once they encounter their first prison camp, I can't imagine that any Siddarmarkan soldier will
ever consider accepting an enemy soldier's surrender. There will be some loud grumblings among the ranks of the ICA as well. Good thing they get to shoot inquisitors on sight!