Warriors died young from violent deaths or infectious diseases, not from a chronic diseases. The appeal to nature is simply following the idea that we are what we're best adapted to, but I agree that working solutions and not always the optimal ones. In this case though, it's more of an attempt to avoid poorly working ones. That's why I strongly believe in having a solid base as a diet and optimize using "hacks" like turmeric and coconut oil, for example. I'm not adapted to those as my predecessors didn't eat those foods, but I eat them and they optimize my ancestral diet further.