Who needs nukes? Ukraine is currently being pumped full of billions of dollars of conventional weaponry, and the Westerners responsible admit that they have no idea where most of it is going. In fact much of it is supposedly turning up on the darkweb markets - which is to say that it's now possible for anyone with bitcoin to buy a Stinger missile.
Think about that the next time you get on a plane.
I tend to lean towards "there's no way to make a reasonable estimate at all" given the lack of oversight, as reported by other mainstream news organizations.
Unfortunately many are blinded to reality by their zealotry on the issue. Others understand the truth, but believe statements of objective reality that don't "support the effort" should never be uttered because it hurts the cause or "echoes Russian propaganda". The truth is that the "fog of war" is a very real thing in every conflict and it is foolish to make definitive statements one way or the other.
Nobody knows Russian losses. Not even Russian officials (though they probably have best estimates, but they will not release the numbers, not until this operation is over). Everything you read in Russian news is Russian propaganda which lowers estimates. Everything you read in Western (or god save Ukrainian) news is anti-Russian propaganda which makes up numbers out of thin air, because West in active proxy war against Russia and its news agencies are just propaganda speakers on the other side.
Think about that the next time you get on a plane.