It always comes back to the fact that assault rifles are the best weapon.

actually i'd have to disagree, due to the fact light machine guns almost always beat them out when i'm even using the l86 lsw, it's actually pretty good with a sight that's not iron sights and grip to keep the gun's recoil down, it shoots fast and takes down enemies with ease.
also, putting stalker on them makes them even better because you can basically keep aiming down the sight and be ready to blast someone, also speed would help with lmgs that don't need two attachments like the pkp since you could basically run around with a 100 round assault rifle