Why does it matter how many hero movies a person is in? Schwartzenegger, Stallone, Willis, Connery, Seagal,....these guys all played numerous different characters, most of which were some kind of hero. Your there to watch the character Deadpool, or Green Lantern, or Captain America. Not the actor, but the character.
BTW I think Green Lantern looks to be badass! Trailer looks solid and by the book. Hal Jordan was always cocky and wise-crackin' and Ryan Reynolds looks to pull that off quite well.