It's always BRD for dungeons and MCH, which will also be dropped until the next expansion, for story and completing dungeon gear sets while leveling leather worker. Then AST and PLD, between alliance raids.

But, hopefully they will separate the sets into different treasure chests for DPS of war, Tanks & healers, and dps of magic or something, because entering Doma Castle with a lv 63 weapon feels really embarrassing