Put ranged to sleep (assuming they're elves, not hunters) with dryad's lullaby along with other level 1-3 units. Got the phantom spell? Cast it on dryads in the third round (when lullaby wears off) and cast lullaby again with phantom dryads, while you pick off any remaining level 4/5 enemies (assuming any are left). By the time the second lullaby wears off, lullaby will become available again to the original dryad stack. Get my drift...?
Also, you got Anga's Ruby, right? It's a must have for a girl army. Hopefully you find sprites, too.