3 Dire Wolves out-classes a full army of Skeletals, by HP, Attack, AR, Defense, Attack Speed, and efficiency. Not only can they be spawned from thin air, they also improve themselves by consuming corpses. Bears with full Synergies is a TANK. Literally, a tank.
Now, they won't be quite as affected by Auras on the level that Skeletals can, they are still able to act, even when against a boss. A Bear is specifically a boss killer.