Those were just four examples I used, but there are plenty of others out there I could have used as well. Gemsbok shouldn't need to be phased out in favor of Scimitar-horned Oryx, as gemsbok are more unique and the scimitar oryx has been popping up just about everywhere in the private sector. Roan Antelope are present in six or seven US Zoos, but a few of them do keep quite large herds. A decent-sized population, but more facilities keeping this absolutely beautiful species would be nice. I'm definitely jealous you have some of the smaller antelope species present near your home! They're some of my favorite species I've yet to see in zoos. And again, I could have just as easily have used any number of other examples for species I wish more Zoos would incorporate into African sections- Slender-horned, Speke's, and Soemmerring's Gazelle come to mind as others in the ungulate realm, but amongst other groups I could think of other examples, black-footed and sand cats, banded and dwarf mongoose, bat-eared foxes, any of the African Starling species, turacos, many of the African Vulture species, and quite literally any African reptile smaller than a sulcata tortoise. Primates is another big area that comes to mind for this. Let's see more Zoos keeping bonobos, hamadrayas baboons, geladas, guenons, mangabeys, and Swamp monkeys!