Oak aspect gives WE's a rare toughness 5 or str 5 creature. Willow can be devastating esp on flank and rear attacks where there are no multiple attack characters. Dryads and wardancers coordinate nicely in making coordinated attacks. Orion is perfectly suited to take out knights and large monsters. Throw the spear and watch knights drop.
Solitary characters watch out.
The horn of the Wild Hunt is wonderful at chewing up your opponent's dispells. After all, even a ld10 unit will get scared 1 of 6 times. With the flyers of the WE's you can count on that being lethal. I once got Thanquel and his bell stuck in this forest. If they moved the bell would break and Thanquel would be stuck guarding a broken bell until the end of the game.