Bersekers are fighters and their role is to take damage, not deal it out.Assassins are scouts whose role is to deal damage.So nothing is wrong with your berzerker.Berzerker can do good damage with their attacks that hit multiple opponents.You are also not making a fair comparison.You are comparing the peak damage done against you with your average damage.Your own peak using a CA should be significantly higher than you average.Assasins with have higher damage CAs but these are often positional - only able to be used from behind, or from stealth.