"Oh, and both are expected to be returning too...... "
Yes, it's uncanny how, as you point out so well, those parallels run so close together. :)
As an aside, what moves me most over the Arthur story, is the belief that he will return in the time of England's greatest need. And I also hearken back to that Romanised Briton (Arturius?) who was so key in the fight to stem the Saxon tide - a fight I believe went on for nearly 250 years after the last legions left to defend Rome's own crumbling defences.