Kaskazi is identified as the first major branch of Mashariki. Its listed components include Lakes, Upland, Langi, Takama, Northeast-Coastal, Njombe, Kilombero, Rufiji-Ruvuma, and Mwika-Rungwe. These labels correspond to linguistic zones extending across eastern Africa.

The passage associates Kaskazi with wider historical movements beyond its core eastern African distribution. A phonologically demonstrable loanword layer from an extinct narrow Mashariki language, apparently belonging to Kaskazi, occurs in Botatwe languages. This pattern suggests that Kaskazi-speaking populations occupied parts of the region before the later expansion of Botatwe settlement across southern Zambia.

A comparable Kaskazi substratum is proposed for Sabi languages spoken across eastern Zambia. The earlier Kalambo culture is attributed to Mwika-Rungwe or other peoples with Kaskazi affiliations, before the Lwangwa archaeological tradition spread across the region.