I'll try to clarify:
There's plenty of posts tagged with cat_humanoid but not cat, do they apply to "humanoid" vs. "anything else" only? So there should be very few posts that have both, unless a standard cat is in the same picture with a catgirl, right?
What about tagging the exact species? Lots of posts with cattle_humanoid but not cattle, but if I wanted to add holstein_friesian_cattle to a humanoid character, it'd also get tagged as cattle.
Not sure if the question is clear...
Updated