The Southeast Chamdo branch (a name that I have coined based on the geographic location of the languages) consists of three related languages.
Lamo (mBo)
Larong (Zlarong)
Drag-yag
Southeast Chamdo is clearly not Qiangic, Burmo-Qiangic, or rGyalrongic, although it may have been part of an ancient linkage of Sino-Tibetan branches stretching from the Qiangic linguistic area into Chamdo. Speakers would have migrated up and down the Yangtze River and its tributaries, facilitating linguistic convergence across independent Sino-Tibetan branches.
Sources
Suzuki, Hiroyuki and Tashi Nyima. 2018. Historical relationship among three non-Tibetic languages in Chamdo, TAR. Proceedings of the 51st International Conference on Sino-Tibetan Languages and Linguistics (2018). Kyoto: Kyoto University.
Zhao, Haoliang. 2018. A brief introduction to Zlarong, a newly recognized language in Mdzo sgang, TAR. Proceedings of the 51st International Conference on Sino-Tibetan Languages and Linguistics (2018). Kyoto: Kyoto University.
Jacques, Guillaumes. 2016. Les journées d'études sur les langues du Sichuan.
Tashi Nyima; Hiroyuki Suzuki (2019). "Newly recognised languages in Chamdo: Geography, culture, history, and language". Linguistics of the Tibeto-Burman Area. 42 (1): 38–81. doi:10.1075/ltba.18004.nyi. ISSN 0731-3500.
Xizang Changdu Diqu Difangzhi Bianzuan Weiyuanhui 西藏昌都地区地方志编纂委员会 (2005). Changdu Diquzhi 昌都地区志. Beijing: Fangzhi Chubanshe 方志出版
Lexical comparisons