Just to check, I hit on purpose several times one of the shipless sailors in Cyseal on the Harbor, the sailor reaction was OK, after hitting him 3 times, all the sailors began to attack me, which was fine, then gradually all sailors in the area (including the ship captain) went to fight. All of this seems really OK to me.
However, no guard came to help (even if there are several close by), and after I killed every sailor which participated in the fight, the nearby NPCs (farmer, guards, etc...) did not bother at all.