The people of Soshangana mixed with the Tsonga people who were then called Shangani. I am not familiar with the Hadzabe but I know a good deal about the Tsonga. If your interest is more than a scholarly I can put you in touch with them. My fiancé is Tsonga and knows much of the history. Below is an article from yesterday’s news on the new Inkosi Eric Nxumalo. There is a descendent of Soshangana living in Tennessee.

Sowetan
01 October 2007
Riot Hlatshwayo

Thousands of people attended a huge feast to commemorate King Soshangana Nxumalo, founder of the amaShangana nation, in Mpumalanga on Saturday. The function was held at Thulamahashe Agricultural Showgrounds and was graced by Mpumalanga government officials and Bushbuckridge mayor Milton Morema. Chief Eric Nxumalo of the amaShangana Tribal Authority, who is a descendant of Soshangana, could not make it to the occasion “because of other equally important commitments”.
Nxumalo is awaiting the outcome of the Hlapo Commission into whether he should be inaugurated as the paramount king of amaShangana. A representative of the Nxumalos, Mpisane Nxumalo, said the day was called Soshangana Day. “We are here to remember our grandfather, Soshangana, for having established the Gaza Kingdom in Mozambique in the 1820s. “He stopped the Portuguese from selling our people to Europeans as slaves,” said Nxumalo. He said that Soshangana was a brother to King Zwide Nxumalo and the commander of Zwide’s generals in KwaZulu-Natal. Nxumalo said that when Zulu King Shaka fought and conquered Zwide it became an embarrassment for Soshangana who fled with his army to Mozambique. “Soshangana conquered several nations in Mozambique and formed the Gaza Empire that ruled over tribes in Mozambique, South Africa and parts of Zimbabwe,” said Nxumalo.