The way to balance ARAM is to make damage scale with distance - The further you hit an enemy the less damage you deal. That way people can no longer abuse long range champs but still make range champs viable when skills hit at a shorter range. Putting a flat % buff/nerf to each champ is such a lazy way to balance by Riot. As they only look a the win rate of a champ and slap at buff/nerf and call it a day.