I’m sure there was a bit of muddling in historical accuracy in the film, but, in essence, I think the director and the actors got it right.
“Zulu” is the rare war movie that, even though at the end one side must win and the other lose, you have a sense of pride in the courage and valor displayed by the warriors on both sides.
The movie is ‘reasonably’ close to “The Washing of the Spears,” by Donald W. Morris. It is considered to be the definitive history of the battle.