The only team that really worked well together:

Zidane (Lvl 69)
Vivi (Lvl 65)
Garnet (Lvl 62)
Steiner (Lvl 67)

And I don't know why all you people are using Amarant and Quina and Eiko. I found them to be very inferior. (Just my opinion, please don't kill me about it.)