The story is BS, as is everything the Germans wrote on East Front.
All these heroic stories do not explain why the German and Soviet losses were nearly equal, not counting millions of Soviet PoWs they starved to death in camps. And since 1943 the situation bece loopsided in the Soviet favor.
Everyone except the Russians have forgotten the old Mongol tactic-lead the invating enemy deep into your vast territory and then pick him off slowly and starve him until he can barely make it home again.