You can compare lots of historical societies, or lots of historical companies, or whatever. Why shouldn't that provide valid data - more than anecdotes, because

You can compare lots of historical societies, or lots of historical companies, or whatever. Why shouldn't that provide valid data - more than anecdotes, because you can have a large data sample? Also, even an anecdote can often prove something, namely the possibility of one thing. If you find one society or company that functioned in a certain way, it is a valueable data point.