From Donald Featherstone's Osprey Omdurman 1898
shows the following British Naval Forces at the battle
Three 1889-class armored screw gunboats(each with 2 Nordenfelt guns, 1 q/f 12pdr, 1 howitzer, 4 maxim guns)
Three 1896 armored sternwheel gunbots (each with 1 q/f 12 pdr, 2 6pdrs, 4 maxim guns)
Four old-class armoured sternwheel gunbots( each with 1 12 pdr, 2 Maxim-Nordenfelts)
So the Naval brigade was there and with several Nordenfelt variants.
So perhaps one could use the EOI RN series in the Sudan?
Randy