the problem with your theory is that as soon as you turn off radar it becomes a shotgun rush and camp fest. I've experienced it time and again whenever I play inferno. And you simply cannot play against shotguns without radar if they are playing properly, not without camping out in a large open space where they can just mida you instead anyway. Either that or you get lucky and they are looking in the wrong direction when you stumble across them. But I don't like relying on luck to not get one shotted by shotgun-whores.