Oh OK.
Well I would love to be able to make hundreds of different set-ups for each and every type of "occasion" but it's not really practical.
If anything they should just let you edit the classes in-game or even just not have classes and let you pick each thing you want during the game like SOCOM 3 and some other games. I wouldn't like been able to select perks in-game through since you get to know which enemy will be using martyrdom/last stand/etc so you can get to know your opponent. I couldn't care less what gun they were carrying since they are guarenteed to have one.
If I can't choose between 2 weapons to make a class, I just use the overkill perk and take 2. One of my setups consists of a Dragunov and the M4 so I can either snipe or run-n-gun at will.