Chen Xi and Zhou Yu didn't rush into the Northern Huns Camp. To be honest, if it weren't for the fact that the Northern Huns had no possibility of surrendering, Chen Xi actually wasn't very willing to resort to harsh measures. In truth, while Chen Xi believed in "the only good Hu people are those who are dead," he also believed in Liu Yu's philosophy of enlightening all people, transforming the Hu into the citizens.
The first principle naturally refers to those foreign clans like the Northern Huns who have absolutely no hope of surrendering, or whose surrender is less valuable than their death. There's no way around it; the Great Han Dynasty doesn't have surplus grain, and Chen Xi isn't the Holy Mother who would starve himself to sustain others.
