Well, you could optimize the seperate squads a bit further, by moving the characters with an AOE special attack to the front and the single target special attack to the rear.
Just imagine the following happening:
you face 3 pests, two of lvl 50 and one of lvl 52.
Both Cactace (single target) and Camellia (AOE) have their special attack trigger. Camellia's AOE deals just enough damage to kill the lvl 50's, but not the lvl 52.

If Cactace attacks first, there's a big chance she'll target the lvl 50. Next, Camellia attacks, but the lvl 52 just survives. Pest counter attacks, your team takes damage, and you'll have to kill it on the next round.
If Camellia attacks first, she'll kill both lvl 50's, but not the lvl 52. But, Cactace attacks next, and the only target left for her, is the lvl 52, which also dies. Result: all pests die on the first round, and your team takes no damage.

So, you'll want to put AOE (Camellia) before Single Target (Cactace) in your setup, just to increase the survivability of your squads as a whole.