Surely either all of that stuff can be found out, in which case it would be easy to fake, or it can't be found out, in which case it would be very easy to fake, because we'd have no way of verifying it.
History isn't just referencing what happened. It's knowledge discovery, which means we have to look at stuff and ask questions, guess answers and then look at other stuff to see whether the answers still make sense.
So say that there was a carpenter from ancient Nazareth. A carpenter would know the different kind of carpenter's tools and how they worked, what people made and how, what woods they used, where those woods came from, how they protected those woods from pests... that knowledge would be
referenceable for the carpenter, while for the historian a lot of it's only
inferable. A fraud could reference the same material as an historian, but when it came to the extra detail he'd have to make it up, and it would only be as good as his research. Ask enough questions, and you run off the end of the research... but if the person
isn't a fraud, some answers will be surprising and new to historians. Then when they cross-check against other known facts, or when new facts emerge, it'll prove accurate.