Before writing, please understand that I used a translator because I am not good at English.
The damage model of the German tank is very strange.
It is based on experience in striking panzer3 or panzer4 with 75mm AP rounds.
Sometimes when an AP bullet hits, it literally evaporates.
Alternatively, determine that the AP bullet hit the wrong place from where it hit the tank’s gloves.
Currently, 75mm guns in the United States have problems performing anti-tank capabilities.
US AP rounds are bad because they have been given their solid shot AP rounds instead of the ones that had HE filler in them. This will probably be fixed when the devs add the ability to choose your vehicle loadout and then you’ll be able to use the better rounds.
I think HE fillers are also important.
but
The biggest problem is that shells do not penetrate the armor of enemy tanks properly.
No - they are just bad - they do not perform like this in WT - they are noit as good as the APHE ones, but they are not this bad.
It really is worrying that so many WT mechanisms have not translated bery well into enlisted - it my indicate some real fundamental problems 
I have also seen Stuarts bounce shots they have no business bouncing, and then magically eat others with no damage to the internals. Ditto the T-34. Something is very wrong with the damage models. 
bouncing has to do with steep angles not thickness a Stuart could in theory bounce an 88mm if it hits from a sharp angle. There is a big issue with the Stuart, literally being unable to pen a puma of all things. or the fact you can put an explosive pack on the deck of a panzer 4 and it doesn’t damage it or any crew. I find myself avoiding german tanks rather then just dying when i skillfully counter them only to be laughed at.