I think it would be cool to have a "Superplayer" playing style in addition to volleyer, defender, etc...
To have this superplayer incorporate all the strengths of the other playing styles combined. (Fastest court speed of the defender, Best volleys/2 additional accelerations of the volleyer, Shot power/max accelerations of the puncher).
Of course, only use for playing against CPU...or perhaps you could just make it so CPU can be superplayer.
Just a suggestion...