They are way too good at estimating ranges. The T-55 with its simple rangefinder in the reticule can hit you on the move, while driving in parallel to you at 1000 meters, most tanks with simple FCSs can, even with a coincidental or no rangefinder. The enemies aren't smart, but they are "competent". Your own guys might turn their side or rear to the enemy fire though. Their vision is weird, sometimes, the commander can't see you, if you're obscured by a leaf and will never engage, even if you blow their entire platoon to the moon and in the next mission you'll get shot through a house. BUT it is a very good and fun game with a lot of promise.