All that chart does is show someone attempt to name creases, not any kind of "standard" in the hat industry. Sorry I am part of that industry and there is no standard to it, just like in the paint industry, there is ni standard to naming colors.
Ad for your San Antonio pictures, I'm guessing that the dates are pretty much late 1880's or later if you see that many "peaks." because that style got very popular about then, was one of Stetson first mass produced pre-shaped hat.
And yes, most hats were sold as 'open/flats" and were either shaped later or not shaped and just allowed to take on a natural shape by use and handling.