There's a bigger problem I hope you become aware as you read more here. First, very smart people are not smart about everything. Second, nearly nobody is smart when it comes to understanding the limits of human understanding. We're bad at epistemology and probability and data collection. Primarily rural settlements from thousands of years ago did not keep accurate birth, death, and marriage records of everyone who was ever born. We can reasonably estimate very broad trends over centuries, but for a specific place in a specific year, we can't say with single-digit precision what the probability is that any random person would have been married ever or died at some particular age of some particular cause. Even now, that is very hard in many places and we use range estimates greater than a full percentage point.
That is the more important point here. Too many are arguing over whether a human researcher might have given more accurate estimates than an LLM. They may have made something more obviously internally consistent, but some facts, including a vast many historical facts, are unknowable. Hopefully, a human would say that and provide a disclaimer that these are best estimates meant for entertainment, not as a source of facts, but I don't think that's the most important point. The most important point is that readers should understand that without needing the disclaimer. Go ahead and spot check citations, but even before doing that, you need to know that no primary source knows the exact percentage of women born in 715 in the Yangtze Basin who ever married or their average age when they did. If anyone, human or LLM, makes such a claim, you should have a very high prior they're bullshitting you and demand to see how they know.
I recall trying to do simple geneaology research and my dad's side of the family drying up very quickly. Mexico didn't even have a census until 1895. The only records before that are church records, most of which didn't survive until the present day, and most of those were never digitized and aren't searchable.