Actually, Quistis and Rinoa are awesome to use

Stick your strong-on-the-edge cards in the corners first, and dont' really try to turn any over.

Then, after the top and right sides are all filled in, and the middle, smack quistis and rinoa down to get 6/4 or 7/3

But unless it's like that, they're pretty much t3h suck. but that doesnt' detract from their usefulness like that^_^