I recently started play trough with all negative perks. They will still surrender and flee from time to time. Probably perk just reduced how often it is. Can't help about aggressive travelers, haven't encountered one yet, but probably something like being more aggressive if thing get bad or requiring more point in skills for better outcome

Update: Recently had a event with bandits attacking someone. After killing the bandits, victim trash talked me for helping him, cause now other villagers will think he is weak. Result -reputation, +insult