A bit more progress: Not all that much, but I really wanted one typical savannah animal. Otherwise, I mostly reworked and expanded exhibits.
I significantly expanded the Arctic Fox exhibit at the cost of the American Bison.
As a non-ingame typical savannah animal, I chose the eland.
I love Rhoetosaurus, by the way, as well as Lambeosaurus.
I have no solution to the Struthiomimus issue though - they continue breeding like rabbits! I have considered sacrificing Cryolophosaurus (spelling?), but I still don't really have a solution.
I did notice that there were no sporred tortoises left (probably, they died of old age, their exhibit was absolutely fine) - and thus I could make the Persian Leopards happier. And yes, a section of path is cut off...
As I already said, deciduous forest is probably the most neglected terrain type (or the mods that I downloaded are biased?), and thus I'm gonna to build a Forest Tarpan exhibit.