I understand why developers choose geographical location (displaying animals that live together in the wild comes across as more "natural" / you can theme an area around it / etc), plus I've heard it helps to build a conservation "storyline" for an area that helps the public empathise. For example, the Goats are next to the lions at Chester because one of the biggest threats to asiatic lions is them being killed for predating on livestock. By putting them close together in a themed area (brought together by peacocks, which are the national bird of india) you can get the public to engage with the conservation work you're doing.
Although it would not have been hard for them to obtain a geographically-correct breed of goat.... which they did not do