Yes, they are still of some use, but the Lullaby is the best strength of all.
To illustrate just how good Dryads can be, I am up to level 29 and Murock in my Impossible Warrior game, and I am finding that Dryads just own everything. This is because most Orc units are low level and able to be put to sleep (except Veteran Orcs, I think). My team is as follows (24,000 leadership):
1200 Dryads
200 Hunters
12 Red Dragons
9 Black Dragons
150 Knights
with 15 Emerald Dragons and 150 Horsemen in reserve.
A standard fight, rated Very Strong, went as follows. This was against Orcs, Goblins, Furious Goblins and Hyenas.
Turn 1:
Red Dragons wait, Black Dragons wait, Hunters hit something, Dryads use Lullaby. Red Dragons use special ability, cast Haste, Black Dragons move closer, Knights move closer.
Turn 2:
Cast Phantom on Dryads. Pick off one stack to destroy using the various units. Cast Thorns with the Dryads, near to the sleeping enemies. Cast Thorns with the Phantom Dryads. One stack is killed and rage is now over 50.
Turn 3:
Use Soul Drain (40%) on strongest remaining enemy. This can be cast every turn now. Hit the strongest remaining stack with everything, making sure that the summoned thorns absorb any hits from the enemy stack. Cast Lullaby with the Phantomed Dryads, putting everything back to sleep. Cast Phantom again on the original Dryads.
Turn 4:
Soul Drain again. By now there are several thorns wandering everywhere. They can spawn more Thorns from dead enemies.
Turn 5:
Victory, losing only 2 Knights. It would have been zero but I was a bit lazy. This is not using Resurrection at all; I only suffered one actual hit from 2300 Hyenas, 1400 Orcs, 2000 Furious Goblins and 2200 Gobins.
Yeah, Dryads are overpowered.
