The eighteenth century being a time of standardization and mass production also leads to it being a time of soldiers all looking the same. There is a certain appeal to that clean and efficient look, but it also gets boring. All of these units are just higher stats and a different look - not really any unique mechanics, but they make the game look more interesting.
Many of these new units are region specific or even require certain buildings and even sometimes monuments to build. This makes these elite units a bit more interesting (although harder to replenish).
izigame.me
It may take some time when the page for viewing is loaded for the first time...