Through open-source research, Mediazona, a Russian independent media outlet, together with BBC Russia, confirmed the names of 50,471 Russian soldiers who had been killed since the beginning of Russia’s full-scale invasion of Ukraine in February 2022.
These are confirmed deaths(with body + passport + certificate + grave, etc.). 450k+ includes casualties (KIA, WIA, MIA)
9 WIA/MIA due to Ukraine killing them for every KIA seems unlikely.
Again, 50k confirmed with all the documents. They might be dead, but there’s no body, or the body can’t be recognized, etc. Also I’m sure Mediazona doesn’t have all the names, and their status.
Basically it’s a process that takes time. If the war suddenly stopped today, I’m sure they would be finding and confirming more deaths for months if not years.