It would be very, very nice if we could tweak the reproduction rate of animals.
i just spawned 1600 with a large majority of prey and just a small amount of predators to keep the population in check but despite that a few years later 1000 have died without decent replacement.
It would also be nice to add some herbivore calamity like overreproducing rabbits attacking villager's fields.
in the long term humans just destroy any wildlife, i'd love some animal farm in there with cow/sheep/chicken (and maybe pig ?) herding