I cannot think of a single reason anyone besides infiltrators would trade their shotguns for a SMG when it comes to CQC. Shotguns are already common pool, and if you use slugs, you can even get them to be highly effective at medium range. For infiltrators, I think it will still be a trade off between Scout and SMG. I will most likely still be running with a Scout/semi sniper for platoon ops for most of the time, since I play DM in those cases, and we will already have 11 other peeps in the squad with excellent CQC weapons. Trying to sneak in and flip terms to pull out a sandy, I can see sporting the SMG AS LONG AS THEY CAN EQUIP SILENCERS. If they can't, I would still use silenced autoscout +silenced pistol + knife. So, it will come down to the question: Will you be able to put a silencer on them?