That's more like what the trust system in FFXI is, you basically summon clones of NPCs that follow you around and fight with you. But FFXI has an entire world that was meant to be experienced in a party and not solo, so it makes more sense there. They'd need to invent a reason to not be alone gameplay-wise for FFXIV, which is the opposite of the direction the game has been going in becoming more solo-friendly lately.