Can't quite remember the levels but I used Frog, Ayla, and either Crono or Magus.

Crono/Magus uses Luminaire/"Magus's tech.
Frog and Ayla can double tech to heal or double tech to do a lot of damage.

Destroy the central guy first then go for the little pod guy on the left after the defense mechanism gets shut off. You shouldn't have to kill the middle guy more than twice if your timing is good.