On the other hand adding one of the two rhino species to another part of the park to keep with one of their many ungulate species could benefit them. People would still see rhinos twice, but because it's not a continuation of rhino exhibits people will be less likely to just speed past the second species because they have already seen the first.
This is an interesting conundrum that zoos face. Geographical or taxonomic?
Well there are advantages and disadvantages to both, as ever. Most of the older European zoos have (or had until recently), very taxonomically-arranged exhibits, with carnivore, pachyderm and bird houses (and of course still prevalent reptile houses).
However, there has been a recent trend towards renovating these exhibits towards more geographically-themed exhibits. Tierpark Berlin, to use your example, are in the process of building a number of Asian themed exhibits and the relatively recent construction of a number of exhibits like Islands around Europe has emphasised an intention to make the exhibits more immersive. Even ubiquitous reptile houses are disappearing, and a number of European zoos are turning to displaying their reptiles in geographically or habitat themed exhibits separately - a good example of this is Chester - a zoo with no official reptile house yet a number of species scattered around the zoo in their various continents and ecosystems.
However, there are multiple problems with this. Firstly, it costs a lot more to transform, say, a pachydern house into a large scale Congo or Polar exhibit than to simply renovate the house and keep the inhabitants largely as they are. Secondly, the maintenance fees are higher because the infrastructure for a specific group of animals has to be repeated in multiple places throughout the zoo instead of just one place (eg. A reptile house is the only place in the zoo needing infrastructure for reptiles as opposed to having terrariums scattered around the zoo each needing the same but separate infrastructure). In a similar vein, keepers assigned to a specific group of animals will have to walk across the zoo to perform their duties instead of just being in one or two buildings. This creates additional problems.
There are also many advantages to geographically themed exhibits. While in a reptile house, the species housed are often from many different ecosystems and hence need different foliage and landscaping. However, if they are housed in a building with other species in the same ecosystem, it is easier to firstly build and secondly maintain these enclosures along with the other exhibits in their ecosystem. Furthermore, the exhibits are more coherent and educational - visitors can see the links between the animals in the exhibit and learn the food webs that exist among the species they are seeing as opposed to the species being lumped together with other animals that sometimes aren't even taxonomically related. This contrasts with, for example, pachyderm houses which traditionally hold elephants, rhinos and hippos, three species who aren't even in the same order.
Zoos like Pairi Daiza seem to be taking this to a new level, creating distinct 'worlds' for different ecosystems and heavily theming each one of them to emphasise the differences and 'immerse' the visitors into each of them. Whether it is effective or not is rather up to the individual, but this style seems to be becoming more and more popular and somewhat echoes some of the exhibits found in North America currently.