
Remember that the power a Primal has is directly proportional with how many aether they have 'eaten' (how many crystals were used in their summoning, basically). Also, different Primals have different powers: Bahamut ripped the world apart because he's the most powerful one, probably related to being the Primal of dragons. The other Primals have their own gimmicks (like Ramuh being extremely territorial), but their raw power is different from each other.