I think between Oryx, various leaks, etc. I've come to assume that UA General Staff numbers are probably optimistic (from Ukraine's PoV) but plausible.

Considering the fog of war, and Russia's own obfuscation from their own people, plus institutional obfuscation¹, the UA General Staff numbers are a good indicator as they are repeatable. It's like if your bathroom scale is always 10% high, you can still use it to track your latest fad diet as long as it's repeatable.