Even half that number is catastrophic for Russia because it totally destroys her image as a super power that can do what she wants,any time she wants,and is impervious to danger herself.
Even beyond that,I am GUESSING that a "fire" has already been lit to overthrow the government,and even though I seriously doubt any such thing is going to happen anytime soon,it is one more serpent climbing up Putin's pants leg.
The whole idea of Russia being a Super Power and immune from attack is now dead,thanks to the corruption and incompetence that will ALWAYS "drive" a socialist system.
It may take a decade or more for the results to start showing themselves,but history will look back at the Russian invasion of Ukraine as the spark that lit that fuse,and Pooty Poot WILL go into the history books in a prominent position. It just won't be prominent in the way he was dreaming.