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So let's take a set back and look at some actual doctrinal and training deficiencies the US Army had in Europe.
Infantry-tank cooperation was poor in North Africa, although it improved as the War continued.
The breakdown seems to have started with the post 1940 doctrine of the independant tank battalions being held in Armored Groups at the corps/army level, the same as non division artillery or engineer battalions. The assumption was that when necessary the tank battalions would be peeled off to the divisions. This created a enviroment where thetanks & infantry at the battalion and company level did not train often enough together. Company and battalion leaders lacked sufficient hands on training with tanks actually present. They really did not understnd how to integrate optimal combined arms tactics with tanks & infantry platoons. Battle experience helped the infantry units that fought in Sicilly & Italy but the experience was not passed on to the infantry regiments not yet in combat in any significant way. That is the non veteran divisions that entered combat from June 1944 had to learn OJT the fine details in their first 60-120 days of combat.
Perhaps had the US more tanks to train with 1920-1939 the tactics of tanks and rifle squads & platoons operating as a integrated team would have been better instilled in the mobilizing army of 1940-43.
The system of Close Air Support was a bureaucratic nightmare in the early phases of the way. CAS requests had to be brought above the Corps level before Quesada implemented crucial changes.
The Marines had gone a long way to breaking the code on this in Nicaragua 1926-32. The Army was aware of the use of CAS in the Nicaraguan small unit battles. A embryonic CAS was contained in the Armys Strike Aviation doctrine. But, somewhere also the way 1932-1943 the concept was lost. The big bomber doctrine came to dominate & what had been thought of as strike aviation moved upwards away from the tactical battle. Maj Gen Dolittle lost sight of the tactical support side in Africa & was lecturing the US Army ground commanders on how inefficient it was to use his finite bomber force in penny packet attacks on front line fighting.
Again, with sufficient funds in 1930-38 the Army can fly both a experimental heavy bomber force, and a tactical force thus keeping up pre 1940 development of technical maters and doctrine.
Logistics nearly fell apart because most French ports were wrecked in the Summer of 44, and unable to be used.
Actually they were still in German hands. Cherbourg was the only operating French port in Allied hands in France in July and August, the Marsailles port group & Le Hrave were added in September, & then Antwerp had its entry blocked by the Germans until late November. The Bereton Port group was not captured in July as intended, nor in September as expected. Middletons corps was insufficient to force the capture of Brest, and grossly to small to also take St Malo, L Orient, St Nazaire, & Nantes as well. All they managed through September was St Malo, the smallest of the group. This was in part because of sending the bulk of US 3rd Army east in August. The original plan of Op Overlord depended on the Third Army turning west & attacking all the Bereton Ports. The decision to turn 3rd Army 180 degrees & send it off to Germany, leaving a single corps to execute its mission was a radical change in strategy.
I'm unsure how aything you might do in 1922 or 1932 would change this. The leaders at and were thinking flexiblly in response to a radically altered situation and tried to take advantage of a incrediblly unexpected opportunity. Underestimating the German defense of the Bereton ports was not a obvious mistake that anything done in 1928 might head off.