Here are my suggestions for a rework of the Isandwana battlefield to add more visual and playability enhancements;

Units to be included: Russels Rocket battery (see pic), The Hale rocket battery consists of 2 hale rocket launchers manned by 8 soldiers and is moved via donkey.

The British units should be limited to the following:
Rocket battery (as above)
2 guns and 70 men of N Battery, 5th Brigade, Royal Artillery (equipped with 2 seven pounder guns).
5 companies of 1st Battalion, the 24th Foot
1 company of 2nd Battalion, the 24th Foot
Mounted volunteers and Natal Police
2 companies of the Natal Native Infantry
This would make the battle even more realistic and will test a generals skill to the utmost!

Visuals:
The camp with its back to Isandwana hill could comprise of tents (see pic) and wagons as well as scattered boxes etc

Isandwana mount:

Make the bottom slopes acessable to troops and many of the retreting soldier made a final stand here (one even held out in a cave).

Sound: The only thing i would add is music samples from the movie Zulu and the zulu sheild banging. As well as the the sound of the bugler when a unit "stands to" or forms square etc.

Just a couple of ideas that would add to this battle as you have brilliantly done with Rourkes Drift.

Modifications to the rate of fire for the british could be upped to reflect how in the actual battle ammunition ran low due to poor resupply, the player would have to consider conserving ammo in addition to unit position. This is a hard map to conquer (i have yet to manage it on normal level) which is a good thing!

Cheers