I the size of your herd limited by your house somehow? I'm in a 4500c treehouse and my limit seems to be 6 of an animal. I'm looking at moving, and a significant consideration is patches. Groddle Meadow 15k houses have 5, 50k mansions have 4, so I'm actually thinking about a nice GM place.
But! The mansions look like they have a bigger back yard. Does that mean they can sustain more animals? Or is 6 a per-street limit?