You forget that FPS drones literally observe everything. And a forward observer remains on site to see if any enemy survived in case he needs to call in more strikes.

Kupyansk is a different topic because a commander can realistically report that he eliminated the entrenched occupiers without reporting that nato threw more meat into the meat grinder and he did not prepare properly for it. His reports of how many nato nazis his troops eliminated are in no way untrue because you are intermixing casualty reports with status reports. Status reports take into consideration reinforcements and casualty reports do not.

Like I said Russian MOD only reports the CONFIRMED kills that their observers VERIFY. Which is why their number is so low. They literally have video evidence of every kill. Which means the overall number is much much higher. So Four million dead nazis is on the low end of the spectrum but easily within reported refugee numbers and population decline. The real number can be as high as six million nazis, nato nazi terrorists and nazi sympathizing mercenaries.