I've opened the save to have a look.
An impressive army! (I also like the power graphs - both the one within the game and the one on the progress page. Fear the Geezers, other teams

)
I like the assault on Ulundi approach. Once the other units have joined the main army, I would walk up to the front door. Possibly, 2 tiles could be used for the attack (but it probably won't be needed - he has no cats) as indicated here:
I agree that Shaka's force in Nobamba will very likely head for Ulundi rather than sneaking back to our heartlands. We will continue building military to back-fill any casualties, and they will meet any of his units who do head east.
Shaka has 2 more cities unseen. Presumably further west. We can leave the furthest, smallest one alive if that suits our diplomatic plans better.
Beginnings of turnset plan
Espionage: re-jig to put all points on Joao
Tech: Put 2 turns into IW. Switch to Currency.
Yas: catapult => temple => axe => cat
Hari: axe => spear => axe
Workers1: finish mine, move to ivory, build camp
Workers2: finish road, move to ivory, build camp
Main Military: Wait until all grouped. Move in on Ulundi. Bombard. Cat attack for collateral. In you go! Back of the . . . erm City!
Then fight the Nobamba division and take that city too.