I think they are evil aiel.
In the age of legends aiel served aes sedai, why wouldnt some of them have served aes sedai who would eventually become forsaken/dreadlords. If normal aiel went from pacifists to what they are now, theres no reason why others couldnt go from pacifists to cannibal darkfriends.
Also, the pointed teeth presumably mean cannibalism, and that suggests they are related to aiel because its another thing about them that is directly opposite. In The Gaterhing Storm, Semirhage asks an aiel how much torture they would need to kill a blacksmith and eat his flesh. I believe aiel being extremly against cannibalism is mentioned other times aswell. Unveiling to kill, and being cannibals is too many ways that they are dirrectly opposite to aiel for these guys not to be somehow related to them.
Even if they turn out to not be aiel, I am convinced that they wont all be channelers (some might be though). For us, the reader's, entertainment, the shadow needs more exciting soldiers than trollocs and fades. Trollocs were imposing in EotW, but battles with the shadow (like maradon) are getting kind of cheesy. No quantity of trollocs will really be enough to make Tarmon Gai'don an epic battle from a non-channeling point of view. Whether these guys are Aiel, from shara, darkfriends of something else, I think there will be alot of them, and they will mostly NOT be channelers. Elite foot-soldiers of the shadow, the way aiel are like that to the dragon.