http://warthunder.com/en/news/4483-development-we-answer-your-questions-en/
ここのこれ読んだ？
Q
Why are many vehicles in the game ‘balanced’ based on whether they have APCR shells?
You yourselves know that the presence of APCRs provides the vehicle a disservice:
they provide a minimum advantage in terms of ammunition assortment, which becomes a reason for an unjust increase in BR.
A
That isn’t always the case. For many tanks, APCRs provide a significant increase in their ability to knock out targets that were previously invulnerable to them.

がっかりしちゃったよ・・・