Uruk-Hai are an evolved subspecies to Maleficent's Goons, aka the orcs. They are quicker, stronger, bigger, and slightly more intelligent than goons. The Cauldron-Born were animated remains of the Uruk-Hai. The Horned King himself was an Uruk-Hai mage, the most intelligent of all the orc races. As it turns out, Vanitas and Riku's outfits had been used Uruk-Hai ninja outfits. That's right, there were Uruk-Hai ninjas out there! Oh yeah, and samurai, pirates, even relatively modern soldiers, but they were rarely used.