I understand where you're coming from OP. And i Agree. Its totally illogical for a medium tanks gun to bounce off the ass of any of these heavy tanks from any faction. The only tanks that should bounce off the rear of heavies are the Luchs,T70,and stuart.
There are times where my sherman assault group pen the rear of a badly placed jagdtgier every shot and end up killing it in under 10 secs.
Then there are times where the the jagdtgier is at >10% health and none of my shermans/jacksons penetrate the damn rear at that crucial moment and they all end up dead with the jagdtiger walking away with a slither of health and vet 3(True story)
This is kinda alleviated with Guards motor and other docs with Mark vehicle. But since the Mericans dont have that...meh.
