Secondly, Ost armour has no where near the impact on the game when compared to some allied tanks.
The issue is not so much that Ost armour does not do the damage that some allied tanks do, but more the fact that Ost armour cannot maintain as much field presence due to how often allied At penetrates. I am aware that axis armour does improve with vet but often Ost is already on the ropes and doesn't have enough vps available to built vet. The other thing is allied armour isn't noticably inferior to axis armour especially when consideration is given to how often axis tanks shots fail to penetrate. I have lost count of how many times I have seen a panther or stug or P4 bounce or miss shots on pershing or Is2 ( many at point blank range from P4 ).
Are you referring to 1v1? Because this is not indicative of the 3v3/4v4 experience.
Also you seem baffled that a Call-in heavy tank such as the IS2 (and to a lesser extent the Pershing) can bounce shots from stock units...