That last statement is incorrect, ps all stars had mostly PS owned/made characters with only a few being third party. You got it the wrong way around.
I had no idea most of the characters were PS created like Fat Princess, but that is good to know. My point is, if the 3rd party characters are more the main attraction than the 1st party characters with the exception of afew, its not going to do the game justice.
I know Smash is doing something similar recently however Smash was created and made famous by Nintendos very own characters.