Witch-Doctor (Sorcerer) versus Sahib (Wizard)
by Marc Saindon"I told the witch doctor, I was in love with you
Doh, doh, doh, doh
And than the witch doctor, he told me what to do"
While it's catering a bit to a cliché, it seems that it would nonetheless be expected that an adventuring party eventually encounters a witch-doctor, especially in the wilder regions of Tangor. One idea is to keep the "Sahib" as the intellectual Wizard who goes to Tangor's Magic University and operates a business-savvy consultant (almost on par with Darokin), while the Witch-Doctor (a Charisma-build) is found either among the poorer classes (who can't afford magic school) or among rural tribes upon which Tangor's imperial culture has less influence upon. Sahib and Witch-Doctors might have a rivalry, with the former perhaps even looking down upon amateurish magics (while getting along better with Tangor's Artificers, who also share an Intelligence-build). Origins for Sorcery might involve divine blessing from a local or spirit, hag bloodline, vision quests, exposure to fae energies, near-death experience, etc. Witch Doctors will use a countless number of titles in varying culture, so the name of the kit is a quick catch-all, but on the terrain, expect other names to be used (Medicine Man, Rain-Maker, Babalawo, etc.).
Alphatians venturing in Tangor will first encounter Witch-Doctors, and thus expect that the rest of the Empire's magic follows similar paths, unaware of the greater resources available as one moves further towards the core prefectures, and thus creating a misunderstanding between Alphatia and Tangor.
Alignment-wise, the Witch-Doctor can go into any direction, with some Lawful practioners serving as community leaders and wise advisors in tribal lands, while Chaotic individuals might outright rule as despots over their folks, or live as moody loners who can curse people for a price. Perhaps some train with, or cross-train as, Griots (Bards), especially in smaller communities in which a Gifted individual would have to play several roles. A Bard-Sorcerer might incorporate dance or drums as his artform.
Notes:
Sorcerer
(Image from: https://www.deviantart.com/grimbro/art/13-Nights-2007-Witch-Doctor-68566220)