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Or maybe you just stick M-88s on a PE-2 and accept the performance loss?
Wonder how much would it be good for VVS to have a force of long range bombers (even if those are not strictly 4-engined jobs) with escort fighters to support them?
That and improved pilot training would have the greatest benefit. Unfortunately both are almost impossible to fix given the climate of terror Stalin created within the Soviet Union.
What specifically is it about a "climate of terror" prevents the Soviet Union from implementing decent quality control and lengthening/deepening its pilot training programmes?