I have to ask again, what stops a daemon army making a detour off the road by a mile and just passing behind an adjacent mountain while ignoring us? They can do so at night where fighting them would be madness.
Um. If they want to bypass us and not fight us entirely, what stops them from doing that at the Karak gates too? Isn't it just as easy for them to do it there, too?
They could just take one of the secret exits, possibly one which we'll never even have line of sight to, and bypass the place entirely.
... In fact, this is arguably even
more easy for them to do with the Karak; because, it being a Dwarf Karak, the Dwarfs likely expected a besieging army to be able to set up around their front gates at some point, and so made some of the exits be way the hell away or just breaking line of sight, so a besieging army wouldn't be able to see secret Dwarf runners leaving.
In fact, what do we do if exactly that happens? What if they ignore us entirely, and just run out to ransack some Kislev towns? I mean, not as likely, but.
... At minimum...
What actually stops them from splitting their forces, and doing both? Sending some to attack the expedition at the Karak gates, while sending some runners out via secret exits, and sending them on the road to the nearest Kislev city?
Why
can't they do both? Attack the army fortified up at their gates, while sending some runners or raiders to go sack some villages? ((I mean, the answer to that could be "They're Daemons. Slaaneshi Daemons, at that. They're not going to be patient and avoid diving on the meal right in front of them." But in that case, that works more or less as well as an explanation for why they wouldn't bypass us on the road too, no?))