Make each of them complementary. For example, have a manager that is great at handling veterans, and a bench coach that is great at handling players.
My philosophy is that, at the Major League level, your coaching staff should be geared more towards extracting performance from Major League talent, not at developing young talent. Leave that to your Minor League system (and hire good coaches too
).
Now, that's not to say that you should ignore the "teaches" category, but as megamanmatt said, look at their strategic tendencies and either manipulate your lineup to meet the coaching tendencies, or shop for new coaches that better suit your talent. In the Bigs, it's all about winning, and you won't get far with a coaching staff that act like college professors if your talent keeps striking out.