Oh you can already surrender. I'm really just not sure how.
My low level merchant got his and his crews ass kicked by some mountain bandits. I'm not sure if I left the battle and save&exit(game mode is realistic, btw. No quitting without saving) the game or did my pc crash in the middle of the fight.
Anyway, when I loaded the game, I was in the travel mode, as always when you load a game. Right beside me and my party was the group of 11 mountain bandits I had fought against earlier. I was on very low health(I think 8%) so I couldn't fight, and the few of my men who weren't killed, were unconsious.
So the smartest thing to do was to run like hell, which I tried to do, of course. The same moment I clicked on the terrain to move, the bandits caught me again. I couldn't fight because I was on so low healt, and I couldn't send my soldiers to fight because they were unconsious.
I had two chances. Leave the battle or... uh, what? Surrender?
I left the battle without a second thought and ran like hell before the bandits started to chase me.
This has happened to me only once. I wonder what would have happened if I had chosen to surrender. Would I have been taken as prisoner? Dunno. Maybe I should try that again sometime.