For me, I would break up the teams as
Strike team -
Edgar, Sabin, Celes, Locke

Right wall (most likely side to get attacked) Terra and Gau

Back up to Strike team - Cyan

This let me send one group directly towards Kefka and Rider without worrying about Bannon being attacked. The purpose is to literally attack and kill Kefka as soon as possible while still letting me steal from him. If I'm not in the mood to hear Locke say, "Couldn't steal!" I replace him with Cyan so I can have as much damage as possible. By setting up a blitz, a tool skill, and a spell or runic, it would let me have enough time to charge swordtech (or bushido) to 4 and let Cyan do quarter slam. The teams are extremely unbalanced, but I've always hated this part. I wanted to get it out of this part because I worry I'd get weakened by the number of forces Kefka has, so this takes care of it ASAP!