I found this interesting reading, particularly the section on what publishing professionals are looking for. OTOH, I was a little miffed that the question on "what periods do you most enjoy writing about" was broken down by century from 17th Century onward. Rosa's Secret runs from the 16th through the 20th. https://awriterofhistory.files.wordpress.com/2015/06/2015-report-final1.pdf
I found it a little hard to follow some of the graphs because I forgot what all the colours meant, but interesting reading the summaries of the results.
I noticed no direct questions regarding combat, famous battles, famous commanders, accurate portrayal of military tactics, weapons, formations, etc.