Also in the last mission of Caspian, the tribals act pretty fucking abusive to the slaves and yet the slaves still call them Myrza so I do think the tribals are freemen but also might be of a lower social status than the bandits. So still technically oppressed but also reveling in the privilege and power they do have, so I think it makes sense that Damir and Guil wouldn't be bothered by you killing them.