I arranged with another lord to attack a Nord castle. The north-men are masters of horseless combat, making their castles exceptionally deadly to siege. I wasn't worried, though. The castle was understaffed, their faction crumbling under a long but successful campaign. My character is skilled at sniping defenders from their walls, then taking and holding said walls with a massive claymore. Even versus Nords.
All I needed was some men to push the siege ladder up to the wall while I took care of business. This lord had more than enough. But mysteriously he didn't show, leaving me to attack with a token "army" of three fresh recruits from a local village. The recruits died in seconds, and my heroine couldn't push the siege tower alone.
It's weird. I suggested that he siege the city, he agreed and did so. Several days later I approached and suggested we start the attack, and he dutifully repositioned. But when I approach the city myself I'm prompted to construct the siege tower, which takes me three days, and after it's done the lord doesn't join the assault despite standing *right there* on the world map. Maybe I have to wait for him to finish the siege preparations first...
Edit: Ah, worked it out. I suggested the assault a second time and this time he said he wouldn't be ready for six hours. Still a bit screwy, but fortunately I saved the game.
Naturally the Vaegir Kingdom is off having a feast as 90 men and 1 woman storm what I just realized is the last Nord holding. It's like they *want* the faction to bounce back.