Joerg wanted to leave when it looked like we wouldn't be able to carry enough food with much less reluctance than Ruprecht.
That's true, and I did overlook that. Still, that was a logistics issue, which is different from "an enemy of god is right there". That said, I'm more hopeful for a rational response now.
Too be fair, we might not need to fight, the dwarves of Dum don't seem hostile, Mathilde's only task is to find out whats going on in Karag Dum and steal the chaotic cup, all of which requires no army.
I think a devout Taalite is going to find it hard to believe that the beastmen are peaceful no matter what we claim, and would likely assume it's a trick or an ambush.