Honest question, so I'll give you an honest answer.
Hunts are in a small way what NMs could be. However, they are a little different. For one, they have no drops in the sense they don't drop any unique items (Just "Currency" and Logs)... Second they aren't really a special mob amongst a group of similar mobs, more so a lore-based NM that roams the specified zone... which Isn't bad nor is it too far from an actual NM experience. I guess what its missing almost entirely is a drop pool. To give you a basic idea of what your average NM was like in the only MMO i played with NMs...
Spiny Spipi - Was a NM Crawler in a lowbie zone that spawned in place of a regular crawler every so often. So basically, You're killing Crawlers, and suddenly one with a different name appears, who is sometimes a bit bigger, a different color even, and a bit stronger. This NM dropped "Mist Silk cape", a low level cape with MND+1 (Other capes of the same level only offered DEF really), so it was a really nice cape for low level healers.
Cactrot Rapido - Was an NM Cactaur that spawned every 21~ Hours or so in Eastern(?) Altepa Desert. It ran around the map with a huge dust trail behind it faster than a Chocobo (so you can't catch it), the only way to attack it was to Link it with another cactaur. This NM had access to 10,000 Needles (very dangerous in XI when the highest HP you'd generally have is 1k~ or so)... it dropped a Bow with Regen+1 (very high utility in the old days) and an Earring that was meh but fun to have. This NM was more of a spectacle to see as a new player than anything, and was very challenging to kill (though I've experienced it done the fun/hard way with 2 RDMs and DoT killing it lol)
Guivre - This NM is a horrible person. Roamed Kuftal Tunnel in a slow pattern and scouted for people to murder. Hated it, but It was still a neat danger. It was a Wyvern NM, and Wyverns were pretty rare to see in XI, so it made new players and sometimes older ones go "Wtf is that". He hurt. But still... it was cool to see and any player, level 1 or 75, was filled with an "Oh god..." sense of dread when you saw him up. He didn't drop anything good, but the fear he induced was worthy of "Notorious".
So what i'm getting at is NMs are more or less 50% the atmosphere and 50% the drops. In XIV obviously the "Drops" would be hard to feel excited about because they can't exactly make interesting or unique items in a game thats entire itemization formula is
<insert Main Stat>
<insert VIT>
Optional:
<Insert Sub Stat 1>
Optional:
<Insert Sub Stat 2>
But It could still add the atmosphere. Killing Cactaurs for your Hunting Log and an NM spawns, Sabotender Mariachi! Drops a ROG Dagger "Bano Del Sol", Level 30, I.lv 35... Neat yeah? It doesn't have to be game breaking or High end content (though I did make suggestions in another thread on how they could do High level NM type content that wouldn't be too far from the norm of XIV)... It could just be there for the atompshere and the drops, even if they were just mid level stuff you'd throw out later. Bonus - Make them Green tier but able to be converted, a nice bonus.
PS Bano Del Sol >
http://www.bg-wiki.com/bg/Bano_Del_Sol -- My most treasured and useless item in all of XI... I camped it with my friends for so long lol.