But this example shows that you can’t trust such stats. They depend from so many different factors, it’s impossible to control them.
This is why the devs decided to use efficiency (which is based on the economy, it’s actually action SL/RP per battle/spawn).
This is also the only sensible way to balance different type of vehicles. Because you can say to use for example K:D to balance vehicles. But then how will you balance e.g. bombers? They need something that can be compared between different vehicle types, and that’s why they use efficiency.
Is efficiency a perfect solution? Of course it’s not, there are definitely issues with it. But there is no perfect solution.
Manual balancing is out of question, especially vehicles can perform differently in hands of different players. There are vehicles my friend loves and he can do wonder with them, but I can’t play them well and vice versa. Even on the forum you can see some good players arguing should some vehicle go up or down. They have opposite opinions, because their playstyle is completely different (even if they are good and experienced players).
Doing community votes about BR changes is a laughable idea - most players don’t play all vehicles, but they love to talk about balancing (this Pz.IV can kill my poor and totally underpowered KV-1! I must vote to move KV-1 down and Pz.IV up, obviously).
I’m not saying that I completely agree with how the devs balance vehicles (I often disagree with some specific vehicles going up/down in BR). I’m just saying that I understand why they do what they do.