Like Mika-chan says, you can put multiple Dress Spheres on one Grid, but you have to play through multiple times to get more than one. But it's not like going through those nodes is all that great. I'd just slap them on for the bonus and call it a day myself.

And it really did flow better using only those three . It was kinda fun, in an odd way, to see their cutscene selves match up with their battle selves throughout the entire plot, too.