Who knows how well the ancient dogs guarded? No source ever really insisted that guarding was their main role. If that medalion whatever isn't largely influenced by apbt I know nothing. I'd be pretty confident in saying it's less pure than the neo and cc, but I can believe it's much better, it looks it. And it may well be bred like you describe- only the best health and character and etc, then all the more reason to be certain it's a mutt.