As said above. Massive disadvantage.
e.g. Having a different loadout with Overkill perk get you your two primary weapons. Then a seperate loadout with Primary, launcher and Ghost. You can then have your 2 primary and ghost if you get 2 loadouts. HR sensor for Warzone is a must really, for other game modes I dont really use it apart from Search and destroy. Othertimes i'll use flashbang instead.
I use different loadouts depending on the map and game mode. e.g. sniper as secondary is good for some maps, but not all.
I was the same as you at first, then I started customising weapons and found it as fun as actually playing the game! I have spent quite a lot of time customising the guns to how i want them, changing and creating different loadouts, using different perks based on maps / game modes and trying different kill streak options
Another example is strange customisations to weapons - AK47 with no stock and 8x scope. I high powered deadly sniper rifle... but loads of recoil.
Or my current primary weapon favourite, Uzi with FFS carbine barrel, no stock, Cronen C480! People have commented "what are you doing with that scope on that gun, you're stupid... bla bla bla" Then I proceed to get a 14 kll kill streak and they all pipe down
