That ignores the massive expansion into Central Asia (Tibet, Turkestan, Badhkashan, Altai), Mongolia, Borneo, the Yenisei Basin, Yunnan, Kachin, the Miao/Viet/Tai/Hmong frontier, and Formosa/Taiwan that the Qing Dynasty (which itself is Manchu, not Han) lead. Modern China is very much a reflection of that mass expansion.
Also, Chinese are not homogenous. Ignoring the 20th century Han social construct, there have always been distinct ethnic and cultural differences among differing "Chinese" ethnic groups like Cantonese, Teochew, Hokkien, Hakka, Guangzhong, etc that were erased during the Great Leap Forward and the Cultural Revolution.