Although, under Zul'ra and a host of other leaders, power within the Horde was currently being drawn toward and centralized in Orgrimmar, each race still retained a degree of autonomy. Quel'Thalas in particular still had its own political system, and the Shu'halo had likewise preserved certain powers, such as in how they handled the Centaur issue.
The Centaur and the Shu'halo were old enemies. With elemental and demigod blood flowing through their bodies, the Centaur had inherited the fury of the elements and the supernatural powers of demigods from the moment of their birth. For survival and release, they had waged war against the Shu'halo for dozens of centuries.
Just like the Amani and Quel'Thalas, the dozens of centuries of conflict had built up countless deep bonds between the Shu'halo and the Centaur. Yet unlike the Amani and Quel'Thalas, who had set aside those deep bonds and joined hands in response to the Scourge and outside forces, the Shu'halo had not spared the Centaur.
After joining the Horde, the Shu'halo, under Cairne's leadership, had experimentally supported Orgrimmar's centralization of power. Once political and diplomatic authority had been transferred upward, the Centaur, Harpies, and Quilboar had at one point all become scourges to the Horde, raiding and destroying its farms and fields.
The Horde had once found those threats extremely troublesome, but after producing large quantities of firearms, those problems were readily resolved.
With the power of muskets, the Horde easily drove off and incorporated the Harpies and Quilboar, while forcing the Centaur out of the Barrens and Durotar. But peace in those regions did not mean the Centaur had found peace.
Since political power had been centralized in Orgrimmar, Cairne spent much of his time there, while Thunder Bluff was placed under Magatha's stewardship. Under Magatha's command, the Grimtotem Tauren