It's very unrealistic the way it work... bad design.
It should have rather a longer range helped with/without a spotter and more hp. Instead of destroying it, rather make the gun decrew and taking a long time to repair if nearly broken dead.
A gun like that should be protected with AA , placed to have a clear los and far enough from the front to be protected for medium arty while still able to kill unit around the frontlines..
Thanks.
