Only an idiot believe that. There is absolutely NO evidence to backup that claim.
In fact, the pro-Ukraine BBC has only been able to find this many total causalities on the Russian side:
https://en.zona.media/article/2022/05/20/casualties_eng
43,460
Russian casualties corroborated by publicly available data as of 2 February
Mediazona, in collaboration with BBC News Russian service and a team of volunteers, continues gathering information on the Russian military casualties in Ukraine. The figures we provide are sourced from publicly available information, including social media posts from family members, local media coverage, and official statements from local authorities.