If the strategy is looking at "what most people use" and "what is overrepresented in the win stats" you will always end up nerfing what is fun and popular.
So I'd suggest smaller changes.. off course fix bugs and stuff that does not work as intended.. but balance a weapon .. and go on to the next. Also decide what a weapon is supposed to do.. sniper shotguns should not exist.. neither CQB dmr's.
Nerfing things on a PVE game that's supposed to be fun shows a lack of creativity.
You can buff the other things while finding better ways to increase the difficulty, instead of just boosting health and throwing more enemies, but that's the "easy" button.
That's just false, you'll end up with Payday 2 where everything is so broken that enemies need to nearly insta kill you from any range to have an actual challenge.
I play DBD, and one of the playerbase’ biggest annoyance is balance by win rate and usage rate. Sometimes an option is just fun and well designed, without being too strong.
It’s especially important to look at what’s fun for multiple players. A good example might be Helldivers 2’s jet pack. Yes, it’s so fun to cover a lot of ground at once, but if the way that’s used is to abandon a cornered teammate to go do objectives while they die surrounded, then it suddenly makes teammates feel slow and useless.
Meanwhile there’s dopamine-driven team synergy potential with the assisted reload weapons. But, there’s not a lot of mechanical information encouraging their use, and it’s pretty simple for people to just use them alone.
I remember TF2’s simple idea where all weapons did more damage the closer you were to enemies, and it demonstrates what I think can be really good balancing design.