Yeah, some guys are really good at counter-battery fire. It helps to have a good idea of where the guy is already.
But it's a double-edged sword; if you spend the opening part of the game staring at un-scouted parts of the map looking for arty vapour trails, you are not supporting your team's advance by destroying or suppressing enemy tanks. If you happen to be looking at the right grid square and you take out the enemy arty early, then it's probably worth it. But if you're looking at the wrong square, then all you're doing is staring at trees while your teammates could have used your firepower.
Worse yet, if the enemy arty is fairly mobile and is smart enough to move after each shot, you can spend the whole game shooting at shadows. I've seen that myself; the enemy kept firing at where I was ten seconds ago, while I was firing at his tanks and destroying them. The guy kept doggedly trying to kill me the whole game until he found himself virtually alone, staring at ten tanks rushing his base.