Greeks, if I guess correctly, had a similar barbarian problems, like the ancient Chinese rules. Superficially, the 2 share the same high-level setting, i.e., an advanced kingdom is surrounded by nomad barbarians, where the advanced kingdom has a settled society built on top of rural + makers + traders economy, with a strong top governmental body; the barbarians are living a much more primitive life, and often trade with the advanced kingdom for things they cannot produce, and often resolve to invasion and looting when the climate cycle degrades their normal life condition beyond the normal capacity of their eudrance.

I don't know about Greeks. Ancient Chinese devote significant intellectual and military thinking and resources on barbarians. Dealing with Barbarians often determine the live and death of a Chinese dynasty. For example Tang, Song, Ming were all ended by barbarians (in the general sense). And the great dynasties of Chinese history is always characterized by a military success and political subdue of barbarians. Han in the Wu Di era, Tang in the Tai Zong era. Ming in the Cheng Zu era.