> It's just that standing stones are sought out by animals for a scratch.
> But that doesn't make them scratching posts (they're still standing stones).

Like you I am suspicious about the idea of farmers going to all the trouble of erecting a scratching post, but you're making an assumption that everything else is a standing stone.

What about cross shafts, gate posts the remains of walls (or in some areas fence posts)?

These are all things that a cow or sheep might adopt to scratch itself on. Just because it's made of rock and stands up doesn't make it prehistoric!

K x