Admit it, when you heard that Nicolas Cage has always wanted to play Superman, you laughed. But then you recall how comedian Michael Keaton turned out to be an amazing Batman, although no one could see it at the time, well, until we saw it. Even those in the business get nervous about unconventional casting. Hollywood executives did not want to cast Marlon Brando in The Godfather because he was washed up, and they thought Al Pacino was too short. But now we can't imagine that anyone else would be better.
That story has happened again and again in Hollywood. Directors, producers, and casting directors sometimes cast against type, or give someone new a chance, and when it pays off, it pays off big.