Stop thinking of it like that. You're making it 1000x more complicated than it needs to be. They are standalone jobs. That means they aren't related to CNJ, or GLA, or anything else. Maybe they'll have a soulstone (doesn't make sense at all because of how it works now...there's no base class to get kicked back to. Maybe you just wouldn't be able to unequip it), maybe they won't, but either way they are basically their own "class" and job and you're not going to keep abilities from other classes depending on which one you equip the soulstone onto.