With luck 10 and sniper perk you score critical hit every time you shoot. You don't have to aim anymore. Aimed shots increase your chance of critical hit but sniper perk makes them obsolete. In that case situation is simple - the more you shoot every turn the more damage you deal. With fast shot you only need 3 action points to fire a gauss pistol. Add to it bonus rate of fire perk and you shoot Gauss pistol for 2 AP. With 10 agility and 2 x Action Boy perk you have 12 AP every round. So you can fire 6 times in one round. With sniper perk every shot is automatically a critical. Add to it better criticals perk and you are invincible. You kill 6 oponents every turn before they even clear holsters.
Beat that with sniping mate. It's pure maths