All units on Nordlig TWICE (a dirty fix for that castle-update)
 

So I don't know much about the Ice and Fire dlc, but on the 'All units on Nordlig'-mod thread, there were a lot of requests to make sure all the units would still be available after some stage of some quest.

I did not do that.

Instead, Runolv the Wise also sells every single unit.
I haven't actually played enough of he game to know for sure this guy stays available as a trader, but if somebody wants another trader to sell ALL-DA-UNITS, I can help make it happen.