Count me in on the two way solution.
Although, exhibit animals would be harder to implement as habitat animals due to the new animations and behavior that need to be worked on. However, making habitat animals exhibit should be much easier, as idle animations are already there.
Snapping turtles, on the other hand, should never be habitat. Otherwise, we'll have snapping turtles floating and swimming at the surface of water bodies all the time, which will look absurd even if the 4 meter limitation for deep swimming wasn't a thing. They are also very lethargic animals. One possible solution to the swimming issue would be having them use the hippo navigation system when they are underwater, but even that wouldn't be satisfactory due to the lack of inactivity as habitat animals.