The art seems pretty easy to pick up from quest dialogue and relatively wide spread. Gyr Abania may have been where it started but there is also mention of it being taken to the Sharlayans. There are a couple people saying "must be Ala Mhigan" but I think that really only applies if one is trying to be a Crimson Duelist (which would seem difficult to be at this point because reasons). The quest is pretty clear that all Crimson Duelists were Red Mages, but not all Red Mages were Crimson Duelists. RDM is actually one of the more open jobs out there in terms of lore.
