Might want to keep in mind that there's pretty much no way Russia has 250k KIA. Usually the ratio of wounded to killed is anywhere between 6:1 to 3:1. Even assuming lots of KIA per wounded (which would seem likely in Russia's case, considering the meat grinders they keep throwing themselves at), it would mean they'd have somewhere in the vicinity of a million total casualties, and based on estimations done by journalists and researchers based on public data like obituaries, social media posts, cell phone metadata and things like that, the number is very unlikely to be that high. I'd buy 500k total casualties, around a third or quarter of which could be KIA.

We'll likely never know the true number, but it's guaranteed that Ukraine is overestimating and Russia is vastly underestimating.