How historically accurate are these renderings? I know nothing about these books, so please feel free to educate me.
I guess they are pretty top of the line. They pull a lot of their work mainly from contemporary printed material which can be a bit dodgy but there is a surprisingly large amount of stuff kept by various armies in museums in Europe and the Americas. The bureaucracies of the day were also recording copious details for accounting purposes. Most troops on campaign didn't look anywhere near as cool as this. If you had seen a real battle of the period you would have just seem large numbers of lines of soldiers dressed in rags of various shades of grey shuffling around a muddy field. I paint my soldiers to be the "ideal" from the books. They look much cooler than reality when they are massed for action on my kitchen table.