It would depend on the type of mats you would want them to gather from Hunting ventures (or if that is something important for you)—DoW/DoM primarily retrieve mob drops (e.g., things like Diremite Webs, Fleece, etc.), while DoL will retrieve items from each DoL’s respective gathering log. If you want more mob drop items, then NIN would be fine, but if you would like a retainer to gather BTN items for you, then I would recommend BTN, if you have it leveled.