There is absolutely no reason whatsoever to use characters that aren't your favourite in that game. The fights aren't challenging in the least. Just go with the characters you want to see interacting with each other, you can check out the rest on your New Game+!
That said, I can't really think of anyone I dislike in that game. I abandoned Lucca on my first playthrough, but used her on another and she is indeed a beast in battle. Ayla is definitely #1 in all aspects though.
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http://soundcloud.com/thundersheep/pandora
http://soundcloud.com/thundersheep/the-first-year