This link is worth exploring. You can click on the map or people names. All these regions border Ethiopia; Blue Nile, Upper Nile, Jonglei, and Eastern Equatoria in the disputed Ilemi Triangle. Traditional material culture and weaponry will be similar in this region. You have to remember that the borders between the tribal peoples in the Ilemi Triangle are modern colonial lines on the map.
http://southernsudan.prm.ox.ac.uk/sudan_map.php