Well, let me rephrase cause it's all kinda hazy. I don't know if he was an NM, but he had a unique name and was accompanied by two other Amal Jaa that flanked him. He wasn't too hard to take down with myself and a lancer, but I thought it was strange him just standing there.
Regarding NM's they are in the game, but they're not free roaming as they were in 1.0 or FFXI. They're a part of the fate system so they have to be coaxed out. Nest Commander pops NE of Black Brush I know. I've also encountered Barometz in La Noscea by fighting flytraps out there.
It's an assumption, but if you see a cluster of a specific type of mob and you continuously kill them, it's possible that an NM might pop. A cluster as in a lot of them in an area, not just 4-5 mobs.
It's not who we are, but what we do that define us. - Batman Begins