Just to inject some expectations into the thread: both nerfs and buffs have and will happen.
Shifting all powers upward to meet the highest performing sets isn't an especially realistic development target, since it means moving dozens of sets upwards instead of one set downward. It also negates any sense of adversity in the game.
By the same logic, moving all sets downwards to meet the lowest performers isn't reasonable either, so those sets will be buffed. Lagging behind and, as you said, spending minutes on a single minion is nobody's fun.
Except for regen. That set is on a mission to find nerf bedrock and we aint gonna stop it now.