The Iron Hoof War Division's envoy is intent on seizing the Heavenly Horse and leveling the Gu Yuan Tribe. Even though they have been driven back by Xiao Chen, it's clear to anyone with discernment that the envoy will not let this matter rest so easily.
How dare a minor tribe under our rule provoke the envoy of the overlord tribe. This is tantamount to provoking the overlord battle division. For the Iron Hoof Tribe, it doesn't matter whether it is the officials making things hard for ordinary people or their envoy's greed instigating issues first. All they care about is their tribe's face. They need to annihilate minor tribes, to deter other subordinate tribes within their realm.