Why do you think Berlas of CE regards the Carelians as cowardly jackals? Given the above, and the apparent backstab that they gave the Empire, as well as the diplomatically near-impossible switch that Caergoth and Suville did (Hey we're at war with the snakes/hey, we're best of buddies), he has quite a lot to be unhappy about.
He wouldn't mind if Carelia got destroyed totally - not a single tear. Serpaents and corruption...look how Carelia started the war after all.
You
are aware that the CE threatened to attack Carelia if it didn't cede regions to Caergoth and Suville as well as destroy all Magna Serpaensist temples and shrines, remove all nobles who follow it from any position of power, as well as threatening to attack Caergoth and Suville if
they didn't agree to a CE-brokered peace, yes? As well as informing Carelia that nothing it did would be trusted and that Cagilan senators would have to be dispatched to check on compliance with the CE's demands?
Caergoth wanted MS out of Ser'quea. That happened when Carelia got pissed enough at the CE to decide it wasn't worth fighting over when there was someone else
ordering a hell of a lot worse.