The setFactionAttackableAbove native AI script function sets the group as being attackable or not by players having their fame matching the specified condition.
()setFactionAttackableAbove(Faction: s, Threshold: f, Attackable: f) // setFactionAttackableAbove_sff_
()setFactionAttackableAbove("TribeNightTurners", 0, 1);
This example code sets the group as attackable by players with positive "TribeNightTurners" fame.