I don't follow you. The only point I was making is that if modern stone scratching posts exist at all (and SL seems to think they don't) then they are likely to be more useful where there are no trees eg Orkney. If that is the case, then despite the geological age of the stones, we cannot be certain of the date they were erected.

I dunno - perhaps SL is right and modern stone scratching posts are a fallacy 'cos farmers don't care if their cows scratch or not. If so, then you still have to consider historical and modern erections as boundary and other markers. As regards the Popping stone - it seems a natural non-erected feature to me and that is how it is categorised on the Portal