Yeah, imma be honest, I've only seen 1 deer at a zoo: white-tailed deer, and it was only one time because next visit it was gone.True, but it's not Planet United States Zoo, it's Planet Zoo, and should be more representative of zoos as a whole. That will lead to a mixed situation with partial realism with zoos around the world - which is a good thing IMO. FWIW I'm also in the US and haven't seen many deer in zoos at all. It doesn't negate the fact that they're in zoos across the world.
However, I do love deer, way more than antelopes, so in my perfect Planet Zoo, I'd want as many deer as antelopes
