Well. We just don't know if Zulu will be in the game. But even if they are not in the game at launch, Zulu will probably happen one day... In industrial, again.
Still, their battles with British are very well documented and rather iconic : because British had very difficult in their campaigns in the land of Zulu.
IIRC, the "naked" Gaesatae directly died in the first moments of the battle despicted by Polybius, which seems obvious, and if I am not wrong some historians think than it was more a ritual move.
Jaguar are naked in the same way in the game, they don't have any armor when all other units have an armor.
Nagitana Samurai is actually not an halberdier replacement, and I hope it will stay like this, Nagitana was not an anti-cavalry weapon if I am not wrong (question of design and conception).
But I'm not a warfare expert, like some people here, so I'm maybe totally wrong.
For the "agressive horde playstyle" mimics, I just don't know if Impi will have this gimmick. It's more a speculation and the horde term (used for Huns and Mongols units) don't seems to refer to an agressive horde of rusher zombies playstyle.
And at the end, a lot of cultures deserve to be in the game. It's the dilemma of these sort of game with historical context. But Zulu deserve to be in too, even if from my personnal tastes, I would have prefered to have Ethiopians, or the Dahomey (when speculated sounded to be an interesting idea).
My point is just than only taking the weaponry perspective to exclude Zulu from industrial, when it could work in a gameplay perspective, is not a good idea for me. It will exclude a lot of cool cultures from the era they are relevant to appear, the Maori for exemple.
And they could fill the niche of a Militarist African culture. The most wishlisted african cultures could be a lot of other affinities comparing to Zulu, aesthete, expansionist, scientist, agrarian, etc ...