I have painted the first of my Copplestone Castings Ngoni. They took longer to paint than Azande warriors but that is becuase their costume is more elaborate. They look very splendid, though, and I have got another five on the go. The shields, in particular took ages!
The shields are the only things I would take issue with as regards accuracy. The figures themselves are very accurate but the shields are modelled as flat. The Ngoni's Zulu-style shields were made from animal hide with a pole threaded into the back to give them rigidity.
Most of the pictures I have seen of them show them as slightly convex with the edge turned up slightly. The Copplestone shields are too thick to bend but I guess it doesn't matter too much as the size and profile is spot on.