Non-humanoid creatures should definitely be kept separate from humanoids for the purposes of counter tags. That said, wasn't it proposed at one point to implement a "#creatures" or somesuch to count the number of non-humanoid characters in an image? I might be misremembering because it was a while ago, but I think the example given was pokemon and someone wanting to be able to distinguish how many were featured alongside any human characters.
Is that something that's still on the table here or did we decide it was too niche of an interest to bother?