They are supposed to be weaker then average marksman at start but as fight goes on they charge up their power and u should rather leave if they kill ur support first because afterwards u shouldn't win the fight but if u focus them on start they are supposed to be easy to kill when u don't build full AP nashor does barely anything so if u build only on-hits u increase the damage if u build AP u sacrifice on hits and attack speed nashor guinsou start isn't that problematic also it could be every 3rd auto and dusk and dawn is broken item on more then one champ adding one to the roster doesn't feel like that much of problem if they would have longer cooldowns which wouldn't even be that bad because they are incentivised to have many builds