It does dependson how important the characters are to your story - but remember that even in Disgaea and FFT there are always some core characters to tell the story as well as randomly generated ones. Telling a character-less story is difficult and rarely done well.
What mostly matters is how you intend your game to be fun. Think critically and ask yourself this question: How do randomly generated characters add fun to my game, and how important is it? Be honest with yourself - if you're having a hard time coming up with good reasons for randomly generated characters besides "It'd be fun", you don't want to add them.