The spear tip appears to be attached to the shaft by means of a tang rather than a socket. I believe this makes it more likely to have origins in Southern Africa, or to groups that left Southern Africa as part of the diaspora after the Zulu wars. It's hard to see from your photos, but I believe the tangs are are usually secured with a raw hide "shrink wrap", and an animal tail skin also allowed to shrink onto the shaft. There are plenty people on here who know far more than me who could correct me if I've got it wrong.
If you look on
www.africanarms.com you will find several examples of spears with tangs and an "x" cross section, Irangi spears from Tanzania, for example.