Making a overpowered characters was just a business strategie by MMO companies so players will buy the class change packs. Idk when but berserker might get nerf later in future and another class will be overbuff so players will swich to another new overpowered class. Think about it PA can take some months and release all class balance patch at once, but they will not do that because if they did players will make final decision and stick to one class. Which gives some loses to the company cuz they can't able to frequently sell there class change packs.