With so many perks in the game now, loadouts ought to be reworked
I think all the perks could be divided (and balanced into) tier 1 and tier 2 perks.
Tier 1 perks would be perks like: BBQC, Surveillance, Hex:Ruin, Enduring, Spirit Fury, Nurse's Calling; Borrowed Time, Decisive Strike, Adernaline, Inner Strength, Fixated, Balanced landing; etc
Tier 2 perks would be like: Monstrous Shrine, Insidious, Mindbreaker, Hangman's Trick, Deerstalker, Remember Me, Mad Grit, Iron Maiden, Agitation; Windows of Opportunity, Lightweight, Alert, Aftercare, Poised, Plunderer's Instinct, Babysitter, Wake Up!, Mettle of Man; etc.
I'd say something like 1/3rds of perks would be tier 1, and the remaining 2/3rds would be tier 2. Some of the tier 2 might get small nerfs. Like, say, Aftercare could be 1/2 survivors, with the 3rd rank in it making it so they also see you.
Then you'd be able to use 3x Tier 1, and 3x Tier 2 perks, for 6 perks total, without being able to do broken combinations of more than 3 top tier perks.
There's a lot of cool perks which just aren't strong enough to fit on your loadout, but they also shouldn't really be buffed. There's just too large of a pool of perks to only be taking 4 at this point, but separating them into tiers can prevent it from power creeping too much and making too stupid of builds.