One quibble is the strict division of classification of cavalry and horse archers given it was not uncommon practice for horse archers to soften up the enemy and then draw swords or spears to finish up with a quick charge and the difference between light and heavy cavalry could be quite small or situational. It doesn't distract from the main thrust of things just reflects that over a couple of thousand years in countless wars across five continents people tend to experiment and change things up a bit. Just felt nitpicking is in the spirit of the enterprise.