As written, rival tridentholders do not have any targeting priorities, only marking priorities. For the purposes of targeting, tridentholders should use the priority list for “Others” as if it was part of their own priority list after its current marking priority of “Hex furthest from an opponent.” Because of this mark, they may well not have a target in their Range, but if they do, they should attack/use targeting skills following the “Others” priority list.