No attack move on snipers? How about this: mouse is disabled, you can only move your sniper using WSAD or arrows keys. That should nerf enough.
Snipers must be controlled using WSAD along with the mouse. Also, you can only control them first person and must manually reload the gun with 'r'. On top of that, you're only allowed to sprint around and no scope people or knife them... and kill streaks. Also the game is now called Company of Duty: Call of Hero.
I think that if they just increased the % chance to miss on moving units, snipers wouldn't be as OP.