After the last set of CTD problems, I ran extensive tests to make sure that "Civ-X" wouldn't cause a CTD problem, and tested them extensively in all ages. As far as I'm concerned, v2.73 of the Wolfshanze Mod is stable with all 35 Civs in all ages. The most likely time for a civ-causing CTD is when you switch ages to Medieval, and once again to Industrial, as both cause significant changes to the ages... at least this is linked to "unit-wise" changes... if there's some sort of graphical glitch in the CitySets (which switch more-often) maybe there's a problem with the African Cityset... though I find that unlikely (are there any other African civs in your game besides the Zulu? Like the Mali or Ethiopians? They share the same cityset with the Zulus). I have just played a very extensive game with the Mali in it, and I noticed no CTD issues (and they of course use the African cityset).
To my best knowledge, none of the 35 Civs in the Wolfshanze mod should cause a CTD as-of v2.73... now of course, I'm not sure if Ninja did any changes to any of the civs, but that's my take on it.