There is one thing suspicious about that drawing: the genitalia is covered up. I was in anthropology for a while and (while I am obviously not an expert) all the "human sacrifice" art we saw featured very naked captives. Genitalia was never coyly covered by a draped cloth or shielded by a bent let. It was always right out there. Emphasized, in fact, as if to gloat over the captive's naked humiliation.
Well, perhaps if they were captives, but the article seemed to indicate they were treated well before sacrifice?
I don't remember talking about that stuff in Anthro in college. Maybe I blocked it out!
sundero