Funny Tom! Show me any game where the rules for balancing are. If games were balanced we would not need things such as Swedidh or ETC comp systems. It is practically impossible to balance any game unless your playing Stratego or chess.
Now as to the original question there are a few ways to equalize the gaming experience. Azyr comp, Lords of War, UK Independent Pool and Clash Comp, Ordo comp, etc. are just a few examples. So far my group has had luck not utilizing anything but the pre game discussion on what everyone brought and what everyone's expectation from the game is. Sure we have had some lop sided model count and power level games but AoS is a scenario driven game. The game really shines when playing for objectives, scenarios and story lines!