For Southern China I propose the following maps:
Jiangnan: covering its eastern coast, literally means “south of the Yangtse River”, and roughly corresponds to Zhejiang and Fujian provinces. I was initially against this name when someone else proposed it, though now I think it’s a reasonable name to use.
Dongting: covering the central Yangtse region and named after the Dongting Lake located in northeastern Hunan, roughly corresponds to the Yangtse River region on your map.
Sichuan: same name and covering the same region (Sichuan basin) as the one on your map, no need further explanation.
Yungui: covering the Yungui Plateau bordering Parallel Rivers (Burma)
Lingnan: corresponding to the Pearl Delta on your map and covering the southern coast, the name literally means “south of the Nanling mountain range”.
And some possible new minor civs that could occur on these new maps (as well as on some of the existing maps):
Taoist Temple: Jiangnan, Dongting, Sichuan, Central Plains
Shaolin Temple (not new but I included it here nonetheless): Jiangnan, Yellow River, Central Plains
Hui Settlement: Silk Road, Mongolia, Yellow River
Tanka Settlement: Jiangnan, Lingnan, Indochina
Hmong Settlement: Dongting, Sichuan, Yungui
Zhuang Settlement: Lingnan, Yungui, Indochina
Cham Settlement: Indochina, Siam, Lingnan, Malaysia
Tai Settlement: Siam, Parallel Rivers, Yungui