This idea has been pitched on this forum a couple of times already, please do a search before starting a new topic.

Each time this has come up it has been pretty solidly rejected by the player base for the following reasons:
1) Accuracy. In a combat situation where you are moving and shooting at targets which are doing the same it is just too difficult to hit anything with dual wielded hand guns. It is unrealistic to use two hand guns at the same time and does not fit in with the overall intent of accuracy (within a sci-fi setting) thus far portrayed in a game.

2) This would make the scrambler pistol over powered. Consider for a moment the damage produced by the current crop of non-militia scrambler pistols. I'm not looking at their stats right now so my numbers might be a bit off but I recall seeing one that did 75 damage per shot and another that was around 100 per shot. A player with two of the later would be able to deal a tremendous amount of damage and fire so quickly as to render the SMG a useless weapon. Just image the player winging and screaming this would generate. "Nerf the akimbo pistols!" "Pistols are OP." This idea would ruin one of the most reasonable, and skill requiring, weapons in the game.

3) Reloading. Currently the animation shows a rather complex series of actions needed to reload the scrambler pistol. Can you imagine the hoops the animators would have to go through to have your character do this with a weapon in your other hand? Either you would have to holster the gun not being reloaded, hold it in your armpit, or place it on the (god forbid) ground. None of these things is either tidy to animate or quick as far as reloading. It would take ages to get both guns full of ammo. Is that really the kind of mechanic you want to play with? A loading animation that takes a minute or two to run through. It sounds obnoxious too me, even before you think about how venerable you would be during the time.

In short. No akimbo pistols.

edit: Holy kitten I didn't see that the OP mentions akimbo SMG as well. That is an even worse idea than the pistols. All the points mentioned here are even greater issues for the dual-SMG. It would be so OP (if you could hit with it) that no-one would use assault rifles. Heavies would choose dual SMG rather than HMG. Accuracy would (if realistic) be so awful that your character would be just as likely to shoot themselves in the face as an enemy. Imagine trying to fine a high rpm smg with one hand. The barrel climb from that much fire would be insane.