I didn't talk about the lack of organs. You can re-read, I meant that their insides (organs) acquire the durability of their element - therefore, Whitebeard's vibration attacks, which, according to the idea, were supposed to turn his organs into mush, did not kill him - bcs Akainu's organs become durable as magma bcs he is magma man. The case with Ace is not indicative, he, like a fool, stood up with his back to block the blow, fire is not durable so ofc his insides were destroyed.