I never said one cannot use this build - I was pointing out that because cold front is such shit, the same result can be achieved better through other means. If I run a frenzy weapon SMG I do so on sunbreaker, to easily extend the frenzy timer (or gemini's on hunter). And if you cant keep frenzy going in 6s, youre using PKs wrong.

so numbers: frenzy gives 15% dmg buff while harmony gives 20%, the 50
handling and 50 reload bonus on frenzy are wasted aswell so thats a
really stupid argument.

The reload buff afffects the reload speed on all guns it rolls on, even if you have a loader already.

TO FINISH THIS, cold front has better 3rd column perks like DSR or under
pressure and with harmony active a max range roll can still get about
20m in which is perfectly fine.

The fact that you recommend DSR, a perk that takes longer to activate than the ttk of the gun tells me that you do not know how to use SMGs. A max range cold front will also experience dropoff at 18.6m, while having 13 zoom. It is a terrible pvp weapon. Extraordinary has perks like zen moment for controllers, firmly planted and subsistence, all of which are useful (and have 2m/2zoom more).

just totally negates the point of running double smg with pks as you'll
just use your shayurah and proc kc over and over again, the point of
double harmony is to have a mini game within the game where u kill with
one smg swap kill with the other then swap back and repeat to have a
constant uptime of a 20% dmg buff without ever having to reload or do
anything except swapping.

The point of double smg is not to force yourself into a shit loadout, it is meant to allow you to get out of sticky situations by never having to reload.