In addition, wasn't it mentioned by Maiev in WC3 that the Kaldorei have wiped out many lesser mongrel races who stood in their way?
I think that the Kaldorei are quite capable of unleashing true fury on the enemy, when the situation demands it. They are definitely not pushovers in the lore, no matter how hard Blizzard tries to make them look weak in favour of the Horde.