How about let's not compare Nerf and paintball ever again, shall we? Just because something works for scenario PB doesn't mean it would work for Nerf. In an actual war, a tank would just make you the crappiest camper on the field.
I agree with rork that paintball and Nerf should not be compared but anyway I may as well try to make a tank, and well I'm at it I might as well make an Armoured train, or a helicopter! (but seriously I am going to try building a tank.)