Yeah, the blade on the throat is the same as a stake in the heart…

“This body might come alive, so we’re making sure”

If a body reanimated, the blade was supposed to just cut the head off. But the move from actual “just in case” routine decapitation and just putting a blade there is a pretty huge leap.

So yeah, primative, but primative because they were advancing, this was the line between an actual decapitation you believed was required, and a ritual just to reassure everyone we didn’t have to keep mutilating every dead body. If modern people started doing it because of legitimate zombie concerns, it would be different.