I'd agree with Haiduk also. If the 203mm was on a SP chassis you would be able to use it in a direct fire mission the same way. If it was towed there it would have to be set up I understand but it wouldn't be used in every scenario just when a situation called for it. If Cm is going to model Berlin accurately, you'd have to have heavily fortified buildings that aren't always going to be breached easily. Of course the Russians used 152mm guns with success but I'm sure they weren't bringing up heavy caliber artillery like this if it wasn't needed. After all Hitler declared Berlin a fortress!