Crunch,
we all know that VVS aircraft until 1944 had a lower standards in term of manufacturing qualities.
But 50% combat loss is far from an argument. Most airforces had far greater "non-combat losses" than anything. This is especially true with single engined aircrafts. And a standard figure in recent days.
And as for Stalin special treatment toward potential icone that could challenge his image you might re-read your history book to understand that Stalin's execution were far from being related o the competencies of individuals.
Pls remind that the history if the 20th century is a bag full of fresh eggs that you'd be cautious about when it comes to step on
~S