Of course there's the fear of tipping the tank over or getting too deep crossing a river since you cannot stand over it and drive
James,
You have obviously never taken a close look at my avatar.
While we can move around the battlefield, you are not always right on top of your tank. If you think driving and shooting is tough, try walking, driving, and shooting. Sometime you have to battle where you are.
8 frequencies is nice for the camera(s), but we ofter run 8 or more tanks PER SIDE. That California midday sun also plays havoc with video screens, not to mention the RF interference from all those motors and RC gear. A few guys tried them out a few year ago. Don't know about the latest and greatest.
If you REALLY want realism, you should have two operators per tank - one the driver, the other the tank commander/gunner. Each would have their own radio and TV screen.