Missile Force Simulation Without Primary Sources

I’ve recently made a bug report regarding the SAM-4s performance within War Thunder using approximate calculations received from a test fire exercise and compared it to War Thunder’s force. War Thunder puts the SAM-4 (CHU-SAM) at 40-43kN of force while in the video the lowest you could even get given lenience is 50kN and realistically around 63kN.

My question is how does Gaijin find these values to use when it is classified information, and the only reliable information is measuring it approximately from, in my situation, a video. Also if these values are temporary values, would the next “most accurate” values replace the pre-existing ones?

I’m just wondering if it’s selective for “balancing” or if they just decide the values on their own and roll with it even if there are no primary sources available. I just don’t know how you would bug-report classified information anyways and how Gaijin would of gotten their hands on the classified information.

https://community.gaijin.net/issues/p/warthunder/i/tNJ3jQGgU2YL