Hello,
What I have heard is that they actually originate from the Mota who are Batlokoa (baSotho). They resided in present day Eswatini as this part of the Basotho before the present day rulers (the Nkhosi Dlamini) arrived. They are called emakhandzambili (those who were found ahead) or bemdzabu (the original owners of Eswatini). With the coming of the Nkhosi Dlamini and the taking over of splinters of clans, some stayed while others moved on to other areas of Southern Africa. The majority of the Mota/Motha/Motsa are in Qwaqwa under King Mota III the reigning monarch.

this info was sent to us by Zodwa Motsa (waMhlaba)