The only experiment I had with the NPC's surrendering came during my massacre and subsequent hauling of all the dead bodies of the peoples of Falkreath into a big pile. My goal had been to teach the guard who made a sarcastic comment along the lines of "let me guess, someone stole your sweetroll," a lesson about why he shouldn't make sarcastic sweetroll based comments about me. Primarily because it would set off my argonian warrior, decked out in full dragonplate armor and carrying a fully imrpoved deadric axe around, and he would kill everyone and make a big pile of bodies.
Unfortunately for my plan, I found that Falkreath was home to two characters who must've been important to the plot, because no matter how many times I murdered them, they kept coming back at me, despite the fact that I was having no problem one hitting them. Eventually I decided to just take them out with fisticuffs, and realized that if I didn't finish them off they would run off screaming about how they surrendered. After this tactic bought me a longer period of time during which to stack the naked bodies of my fallen victims, I had begun to think that they'd just run off into the wilderness, never to be seen again. Unfortunately that was not the case, as in the fullness of time they would return, having somehow forgotten how I beat them within an inch of their life the last time, while they picked away measly portions of my health which almost instantly were regenerated.
So, my guess is that the bandits who surrender would not prove to be too much more intelligent. Chances are that while they might run away for a while, they'd be back in no time for a second helping of foot in their asses.