Arguably the best medium infantry unit of the Dark Age, Spathatoi are a force to be reckoned with, being a Swordsman unit that comes into the game one age earlier than usual. Their only drawback is that they cost metal instead of timber unlike other infantry units, and they also cannot be upgraded to Espadachines in the Imperial Era. But, given that you control so much punching power in such a weak unit at the start of the game, what more could you ask for? just keep them from enemy heavy cavalry, and these units, with their rather cheap cost, will easily overwhelm the foe.