Another thought is that not all ammo was the same. In my tank simulators most of the tanks carry at least 5 rounds of Special AT where sometimes the penetrating power is 50% more than the standard AT round.

If you were in a Sherman 76 and were taking on a panzer IV you would choose standard AT, however if you were up against, say a tiger, you would choose one of your magic bullets (Special AT) (armour piecing discarding sabot or tungsten core etc) and hope for a penetrating hit.

That would add spice to any combat, the germans too had special ammo for taking on the the Russian heavies.

Some anti tank dedicated units had half of their ammo loadout as special AT, eg the M10 and M36 units.

Merry Xmas

Alan