There's a view (which I don't share) that tradition creates credibility - how Roman is that? The Greek pagans are doing what most reconstructists have always done and created a cult of their own for fashionable alternative - or just as likely, the buzz of doing so, of being slightly rebellious and exclusive of mainstream public. For that matter the Romans had shown this sort of behaviour too, with egyptian and Syrian cults proving hard to subside. McEverdy is looking at established and recognised pagan religions in the early medieval world, but of course, his attention is only on such religions within the otherwise Christian sphere. Into the medieval period for instance the Teutonic Knights and other crusaders fought deep into what is now Prussia and Lithuania against people who were definitely not Christian.