In this roadmap post:
Gaijin said the following:
However, this new approach may lead to situations where certain individual vehicles are more effective at earning SL at a given Battle Rating than others. In such cases, we may use other methods, such as adjusting the vehicle’s Battle Rating, modifying its technical and combat characteristics where possible, i.e. altering access to certain shell types or adjusting reload speeds, or applying general balancing factors to all vehicles in that class. To clarify, we will only be changing soft factors such as these, and won’t artificially alter any elements such as armour thickness or top speed etc to change a vehicle’s performance.
This is not a universal issue, but if a player hovers over any high tier ground vehicle (9.0+), chances are it has some notable discrepancies between its IRL and in-game armor. Most will be under-protected, while a minority (primarily USSR) are substantially buffed.
The strange thing is that Gaijin does not treat these as bugs. Example:
So if these aren’t bugs, Gaijin does this intentionally. And in the context of the roadmap, doing this will only harm the already horrible relations between Gaijin and the player base.