The thing is, they aren't that great because they only negate enemy bonuses. They don't gain many bonuses themselves (we'll discuss probabilities separately, as they are AVERAGE in terms of characteristics). And they don't negate all abilities. The fact that they negate abilities doesn't make them stronger. The level is used to reduce the level of the opponent! BUT NOT ALWAYS SIMULTANEOUSLY FOR ALL ENEMIES (I'M TALKING ABOUT ABILITIES, NOT THE BASIC SKILL, AND BALANCE IS ACHIEVED THERE). BALANCE CAN BE DISRUPTED BY PROBABILITY-BASED ABILITIES OF CREATURES! BUT AGAIN, THIS IS A TRADE-OFF FOR AVERAGE CHARACTERISTICS!