We may not know the final truth yet but the losses announced to the public are different thing than those reported in internal reports.
There has always been a certain "gray zone" in losses, but in a Air Force, as in other large organizations, it is more difficult to cheat in internal reports. If you have reported that you have lost three aircraft and two pilots, it is a bit difficult to then ask for seven planes and 5 pilots to replace the losses. And if you only ask three planes and two pilots, after a few rounds what you do, informed your superiors that your pilots and planes had disappeared somewhere or you deserted to the enemy's side? A small tweaking can probably be practiced, but if a lot of machines were lost due to technical reasons, then quickly in the Soviet Union there was a charge of sabotage , which was a life-threatening charge there. On the other hand, if you reported too many losses due to poor training or weather, you could easily be investigated for needlessly endangering the lives of your pilots. At least since 1943, for casualties in the fighter units in the Red Air Forces, the squadron leader or regimental commander had to give an assurance that the assigned task was proportionate to the pilots' training and experience.
And then, of course, the fact that the aerial victory claims of some of LW's top aces clearly match the information found in the Soviet archives better than some others. The same phenomenon occurs, for example, with Finnish aces or, for example, with the British in relation to the surviving LW documents. And the archives of the Red Army, Navy and PVO (air defence branch) have been preserved quite well, except for the chaos of the year 1941. And one could research them for a certain time period after the collapse of the SU before they closed again in recent years.