The "meta" is defined by what is most popular, and there will always be a most popular. With the exception of a few weapon perks, it seems like most weapons are fairly balanced (delicate tuning and Precision Instrument need nerfs). I wouldn't change much from an archetype / weapon type level - I would nerf individual weapon perks and then possibly focus on nerfing individual weapons. The other issue with balancing the sandbox using the "meta" is that the meta changes depending on what skill bracket you look at.