Feeding Frenzy: dangerous spell... for caster?

[Tyrian]

Recently I have many defeats due to this spell. The summoned fish are to weak for causes any damage, and they are summoned in great number and quickly block the way for standard unit (who have a chance to kill). So the battle end when all my troops retreating because they can't make damage to the adversary...
I think the small fish must have a better damage capacity, or an armor percing, simulating the fact that small fish can strike in armor weak point. The spell can have a highter cost for balancing purpose.