Eventually there are going to be similarities in characters. Look at Hogan and Billy Graham. This would mean Cena is somewhat of a copycat; He's a pro-america, superman, limited moveset, big man character aimed at children (like Hogan).
CM Punks character is essentially the anti-norm; He doesn't drink, smoke or take drugs, he's self-righteous, his beliefs are more important than yours, he's better than you as person because of his beliefs and has no weaknesses (both in the ring and outside in his personal life because he has no vice) etc
Before that he was the guy who took a stand against Vince and wanted to "give the fans a voice" and initiate change.
Bryan was just the "best wrestler alive".
I would say no; there's more to his character than just being "the best in the world" and people overlook things like that. Every character has similarities, but it's subtle differences that makes them unique. Just like every human being is influenced by something else and live their life by morals that have influenced them.
Just read the raven thing; i'd say he was more Charlie Manson than Raven. Down to the head shaving and his beard, it was eeriely similar (that's if you know anything about manson)