In the beginning, I tried to settle as more area as possible. Shaka attacked me due to our close border, but I had most of my units there because I assumed Hannibal could attack me, before he attacked Mansa Musa. Anyway, I wasn't well prepared for war, because Shaka had metal, and I had horses, so my warriors defended vs impi, and chariots vs axemen. At the start of the war, my fortified warriors repelled his initial impi attack, and I counterattacked him, killed his Impi with more warriors, killed his axeman with chariot, and took his border city(impi was on open terrain, blocking my chariot attack path, and axeman was the only unit in his city, which was Shaka's blunder). During war I connected metal. War lasted for many turns, and Shaka capitulated after losing more cities.
Although I often don't know if I'll achieve conquest or domination victory, this time it was obvious to me that I'll dominate. So, I decided to ignore Sitting Bull in my conquest plans, because he was far away, with worst land and it is hard to vassalize him. Also Persia wasn't needed for domination victory.
MarleysGh0st, I won domination victory the same turn you wiped out Willem