I don't follow what you mean by a 'buff' class. Arcanist has all of one buff (Eye for an Eye) and the rest are debuff DoTs. The class with the most buffs is conjurer, but then that's part of their role as healer. Arcanist is a DD first and, at best, a half-arsed healer until they equip Scholar, and even then it's not as much of an improvement as it should be over White Mage, though that Galvanize buff is sublimely obscene. I don't think you understand how to fully use arcanist's varied talents.