Honestly at this point there is no real reason to not add Nile Crocodile to Vurhonga except for the mythical Africa 2.0 that won't be done until development is nearing its end for this game (despite the fact that in reality there's probably a good 6-7 possible African reserves that could be made).
To make sure we don't have to have the entire rest of the Dangerous 7 on the same map, I think crocodiles should be added to Vurhonga. It has a lot of water, swamps, rivers - places perfect for these beasts to ambush us from.