Psycho Pirate I think is a big enough deal, or can be made a big enough deal, to lend story logic consistency to the whole shebang. Bane got his hands on a Crisis-level player that can even keep like, Martian Manhunter in the dark. Obviously Bane is smart enough to know that he doesn't have the expertise to "use" Psycho Pirate, and that's where Hugo Strange comes into play.