I'm A Banana
Potassium-Rich
That role was reserved for human groups like the Huns or the Vikings.
In mythological terms, other "human groups" were almost always alien bizarre magical creatures anyway. To anyone in their path, the Huns were most definitely inhuman monsters. The D&D orcs (which can be very Hun-like) fit such a mold quite well.
Orcs are a Tolkien thing.
D&D Orcs bear little resemblance to Tolkien's corrupted evil. Orcs in D&D today owe more to the Huns, to "Dark Continent" style Africans, to Polynesian islanders, to native Amazon tribes, or even more "warlike" Native American tribes....all human groups. But in fantasy, humans with a different culture (and maybe a different skin) may as well have sprung fully-formed from Faerie. Fantasy humans are more normally a specific *kind* of human, rather than the true diverisity of them.
Which, I suppose, is a pretty good reason for pushing Orcs (and other D&D humanoids) to the background. If you've got humans as diverse as they are in real life, rather as narrow as they are in myth, you've lost the need for some of those "inhuman" humanoids.
And frankly, after years and years and years of weak tea wannabe Tolkien clones, I'm having tons of fun stretching out in directions like that.
But D&D orcs, at least in 3e, aren't really Tolkien clones. Hobgoblins, actually, do a slightly better job of that, but even they are only about as Tolkien-esque as Grey Elves.
D&D orcs would be more at home in the jungles and savannahs and Mad Max style postapocalyptic leather-daddy deserts than they would in Middle Earth.