When designing a world with advanced parameters, how to increase the number of animal people?
Solution 1:
Humanoid (and giant) animal creatures are native to savage biomes, so increasing the savagery of your world might increase their numbers as well. Keep in mind that typically only elves settle in savage regions, so cranking up the savagery of a world too much could shaft the other civilizations. At the extreme end they might even struggle getting enough initial site locations at world gen.