How would they not know the terrain in WW2? These guys poured over maps and sandtable terrain models endlessly so that they knew where things were. The problem is enemy troop disposition and placement - which the game replicates well. Intel would have an idea of what the opfor had and approximations of where, but those obviously aren't static. I don't see much of a lack of realism...btw, it is just a game though. Maybe if you're too awesome for the game you should play something else?
Yes, I know, that was a jerk thing to say, but you have to admit, then tone of his post is deserving of this response.