Hmong (our actual ancestors of Hmoob dawb and lees), as a whole ethnic enclave, never played any major role in the Warring States era. By the time the Warring States period came over what is now China, ethnic Hmong were scattered, non-unified, and subsequently didn't have the ability to resemble anything of a "state" or "kingdom".
Every enclave of people united under one state/kingdom (Qi, Zhou, etc.) was absorbed by Qin and eventually all became as one people under the "Han"(-Chinese) ethnicity. This is why there are still genuine ethnic people such as Yi, Yao, Zhuang, and of course, Hmong - because these groups were not unified as one state/kingdom and hence, was never absorbed by Qin.