Where is the view on it now? I thought all tanks had that cupola view. Since there's two guns I'm assuming the 2nd small gun on top, the 37mm, doesn't have one, and that the main gun view is from the drivers position? You could open up a can of worms on this one, as many people want 2 person tanks, this adds pros to that argument, having two views, a driver and cupola, could be a nice new feature.
And not to get off topic but I would make two person versions of tanks and keep the single person versions for maps with lots of tanks, use the two person tanks for maps with 3-5 tanks or less.