I get that zoos IRL don't abide by natural overlap. But the gameplay mechanic for PZ clearly did have that in mind up until the capybara. You can already house animals like cassowaries and pygmy hippos together just fine. They just don't get enrichment from doing so.
I suspect that the elephant-proboscis monkey case is the former being a stand-in for Bornean elephants, while the rhino-tommie case is just the devs copy-pasting the species enrichment from another savannah animal and overlooking the range gap. Here the capybara's species enrichment is very deliberately chosen to be every remotely South American herbivore already in PZ (even when it goes against the base-game grain). The only explanations I can think of are an appeal to memes (as already mentioned by another user) or glaring levels of haste.
Edit: I now know the unicode emoticons will turn into emojis even when other characters are next them
Thing is, the game never used overlapping ranges.
Ever since the beta, many of the African grassland animals in the game would have never met one another in the wild, yet get enrichment from one another (for example, the reticulated giraffe of east Africa and the springbok of South Africa and Namibia).
That in addition to the ring tailed lemurs abd ref ruffed lemurs, animals from different parts of Madagascar, enriching one another since the latter got added. Later expanded with the black-and-white ruffed lemur.
With the Southeast Asia Pack, it became even more notable with the Malayan tapir getting enrichment with the primates from Borneo.
You can argue that the case of capybara-giant tortoise is more extreme than these examples, but the statement that interspecies bonus was limited to animals with overalapping ranges or for stand-ins is flat out wrong.
