For discussions on all matters relating to personal development, religion, philosophy, psychology and so on.
John was the initiator of Jesus, and of quite a few other disciples, and then Jesus went on to initiate others. Every true adept--no matter how high born--must be initiated again whenever they take a physical birth. Jesus was in effect, John's successor, although he admittedly had much different role to play.
Arthur, otoh, was not an initiator. At least no myths mention that. He was temporal king, who, along with Merlin--a mystic adept-- put a major spiritual spark into the British isles. At least that's how I see it.
Who knows what actually happened...