With shottys and fusions (more so fusions) you need to be able to predict an enemy's movement. SOME people who snipe (more likely the unskillful ones) just stare at one hallway, leaving no room for any sort of prediction or map awareness. Fusions on the other hand require precharging, which makes it so that people used to the sniper cannot use them effectively. Fusions can by far outrange shotguns, and I think of my self as a pro frifler. So, in my opinion, the only thing that needs fixing on snipers is aim assistance after scoping in for a certain amount of time, not in general.