Also, order the girls within each squad by how many targets their special deals damage to. Ideally, you put AOEs first and single target abilities last. The idea behind this is, that it will occasionally reduce overkill on a single unit.

Say, you have 3 girls. Two are single target, and can each reduce a targets' hitpoints by 60%. The third girl is AOE, and takes 40% hitpoints from the target.
Now, you have 2 targets.
Single target girls end up both attacking (and killing) the same target, then the AOE girl comes and takes 40% off the second target.
Or
AOE girl deals 40% damage to the both targets. First single target girl finishes of one target, other single target girl finishes off the second target.

So, it's better to have the AOE girl attack first.