There is Only 1 Unit Type in MOBAs...

RTS's have a bunch of unit types but MOBAs just have "champions." Therefore all those champions have to be equal yet hopefully different. There equality and/or inequality comes from the traits they possess. If champ 1 has a pull and knock-up, and champ 2 & 3 have a pull with a slow, then something is wrong if champ 4 has a pull, knockup, wave clear, heal, ranged poke and huge ult. Pulls are good to focus too, because they are engages and being able to engage is an extremely valuable trait. Pulls are the safest engages bc they do not involve committing, and safety is also very valuable. Combining those two things make pulls they most powerful single spells in the genre. No pull champ should ever be able to carry and this is illustrated by several champs across the entire genre whose basic purpose is to pull. If a dev doesn't know this, than beyond college they need another intensive training ground that teach's the theory that goes into this genre. Given champs are the single only unit type and have to be equal how can A. Sol and Sylas coexist? This is all basic common sense to me, but it is also worth mentioning that damage in itself is a tool (or trait). The more of it you have, like anything else, the less you do of other things.

tl;dr It is not like Tryndamere, A Sol, or Kassawin can a bunch of different things.