The most UNPOPULAR faction in Heroes 5.

imba - imbalanced, in short, it means imbalance. Rune magic is simply overpowered, it dominates everything. Try to defeat a Dwarf in a duel - you'll understand why. It's a different story in a regular game. Here, resources are limited, and you won't waste them so easily. But still, runes are cheating.
And yes, Zerks are really useless, they die like flies. I never build them, as there are already not enough resources.