I think this particular case is more highlighting the problems in social science generally. They cant do properly controlled experiments, even if ethics aren't considered most of the time its not even remotely feasible. So the closest the field ever gets to doing proper science is with observing animals and then trying to extrapolate that to humans in a very generalized way. I think Peterson's line is not so much that human's "natural" hierarchical structures are morally sound because they are "natural" more that going against the order of things will inevitably lead to --insert string of hyperbole-- untold chaos and destruction or whatever. Everything he talks about whether it be freedom of speech, parenting, gender identity seems to end up with the basic fundamental idea that we are potentially headed for some kind of socialist apocalypse.