I see no reason to believe ancient Hebrews thought that long time ago animals talked -- or considered snakes to be the smartest animals.

I suggest that Genesis 3 is actually some (admittedly weak) reason to believe that. But, for the avoidance of doubt, my conjecture is not that they thought all animals talked, and I am not suggesting that they thought any non-human animals talked post-Eden.

According to this, at least some ancient-ish Hebrew commentators thought that "The snake from creation was an intelligent animal that talked, thought, and walked upright like a human". This is already long after when Genesis 3 was written, of course, but it does at minimum make it clear that this was by no means an unthinkable thought.

"indicates a deficiency in their understanding", so what?

So that's exactly the point of people saying "ha ha, your religion has a talking snake in it", and they need not be making an error in going from "this religion's holy book has a story with a talking snake in it" to "this religion is less likely to be right than if it didn't have that story". And the fact that magic or divine intervention could obviously (if either existed) make snakes talk doesn't invalidate that.

You misunderstand my position.

No, actually I wondered about saying "except that it's more like incarnation than possession" but decided that was unnecessary nitpicking. So yes, rather than "of my sample of three, one basically agrees with you and two flatly disagree" it would be more accurate to say "of my sample of three, one kinda agrees with you and two flatly disagree".

The sample, by the way, consisted of the books I happen to have on my shelves that I could tell from the titles were likely to express some opinion about the question. I looked in one other but it turned out not to. So no cherry-picking here.

(But I should add that I would not expect randomly chosen Christians to be much like random samples of those three, because most Christians are theologically unsophisticated; so some version of the serpent=Satan theory might well be more popular than that sample would suggest.)