Generally what I do is put Sabin, Gau, and Cyan into one group.. have Sabin Fire Dance, Cyan use his Swordtechs and have Gau use the Hazer Rage since he has Bolt 2 from that and more often than naught, he uses the spell on all of the enemies, eliminating them all. Terra and Edgar are in another group -- Terra uses Fire on them all and Edgar uses Autocrossbow. Locke attacks in the last group, while Celes uses Ice. I keep the group of three in the area where two lines of soldiers come in on the left and on the other side, Celes and Locke are on the far right and Terra and Edgar are in the middle....

....

But that's just me. ^_^