South has been described to have quite a lot of warrioresque peoples in them - my own Sekalyns included -, so I would have imagined an aggressive species would have harder time there than in the barbaric west... Unless it is even farther south or the Sekalyns (and other human peoples of the region) and del-korm somehow can coexist. The niin - who are also southern - are inherently even more chaotic, but by description are generally slightly more agreeable? (Although I still find it surprising niin have managed to avoid extiction.) The xuhrl-njok sprynes themselves are thorough sociopaths and haven't been eliminated by the peoples adjacent to them, either... Weren't large parts of west also canonically described as constantly warring?