John Cena is “the most prepared actor” Peter Farrelly has ever worked with. The 67-year-old director has returned to his comedy roots with Amazon Prime Video’s ‘Ricky Stanicky’ and he revealed he knew wrestler-turned-actor John, 46, was his leading man after watching him in ‘Peacemaker’. He told The Hollywood Reporter: “Someone called me and said, ‘Have you ever seen Peacemaker?’ I said, ‘What’s that?’ That’s not normally the thing I would watch. I kept watching and was like, This guy is unbelievable. The stuff he does in that show is hysterical, and as soon as I saw it, I thought, ‘That’s Sta…