This game is really amazing, so thanks to the developers. The only thing is that when I fire a grenade launcher at a wall or building, or even use some of the lighter cannons on tanks, there seems to be no impact on building or walls at all, regardless of how many times you hit it. I think that this should be improved to add realism and there should be more damage from smaller explosive devices.
Also, it takes two tank shots to destroy a building or wall, and I think that in the real world, one would suffice.
Also, some churches are indestructible.