Well, he could blow up Russia, THEN blow up Turkey at his leisure, but its more obvious for Germany just to take his 4 factories north of you and his 4 objectives and pour units into your last bastion.
I’m not a fan of KGF (at all or anymore), it does nothing to slow Germany down, reduce its income, or tie up more than 1-2 turns of troops. Pouring all your resources into the Atlantic US1-4 is a recipe for getting VCd in the Pacific or, barring that, an overwhelming Japan that backdoors Persia and Russia. Add to that handing 3-4 neutrals to the Axis that they can use to bulk their troop stacks, and its a more difficult…perhaps tenable KGF plan, not sure.
Even if Germany is totally snoozing in France, he has to be totally asleep to miss the USA buildup, still his mobile units can travel through Normandy or S-France without blitzing and blow up whatever lands…the geometry of Europe is far too favorable to the Axis (all defense areas are 2 spaces from build areas).