I thought it was interesting in the Hannigan interview that Hannigan says he only puts down a "1" (fastball) or "2" (Breaking ball) for Arroyo and let's Arroyo decide what flavor to throw. Of course, Hannigan is also determining the location, but it doesn't seem like it's that difficult to do. (Note, I'm not saying catching is easy, but Arroyo seems to do more of the "thinking work" than most pitchers do)
I'm sure all the pitchers prefer Hannigan, but maybe it would be best to use Hannigan on Chapman fulltime (since Chapman is the rawest) and share catchers for the others. All the other guys, even Leake should be experienced enough to shake off a bad sign.