If you look at a competitive game in the pro scene on the DGL you will soon notice how everyone playing competitively just picks the VAL on Insurgent side or the EBR on security, sometimes you see like two guys playing shotgun because its the one hit kill on breacher class, this is boring to watch if everyone plays the same weapons, EVERY gun should get a slight damage boost, not only would this make the game more like the old Insurgency, it would also make the pro games more interesting to watch.
VAL/EBR players tend to always have an advantage by beeing able to kill in one hit.
Since you can't nerf these guns because they would then be useless, just buff every other gun.