Yeah that's where it comes down to what kind of disaster scenario you're actually thinking about preparing for. Though there's no amount of post disaster perusing of those Army manuals summarized by an LLM that's going to help you actually implement anything in them. The skill to use the info in those books without being a liability to yourself and others requires actual practice.

Also the way groups actually survive scenarios is rarely around actual fighting and is vastly more dependent on actual survival skills, cooperation, and organizing. The lone (or small group) survivalist fantasy is mostly an American larp.