The debate over naming Operation Overlord heroes starts with things well before the actual invasion.
COSSAC was a junior staff who had to accept what they were given, not ask for what they decided was needed. They came up with a three beach assault one problem of which was the mixture of landing craft promised "bore little of or no relation as to numbers and types to the actual requirements of the proposed operation". COSSAC had produced a plan where "the foot was cut to fit the shoe". This plan was debated at Quebec in August 1943, Churchill suggested a 25% increase in the assault if possible and Marshall agreed, so COSSAC knew it could try for a larger attack. However for some time post Quebec the agreed landing craft allocation was the supreme plan, Overlord came second, despite that it was supposed to be the other way around. After the allied Mediterranean command team came into the picture it became 5 beaches which resulted in people today strongly claiming it was the good Mediterranean general who made the change, with everyone else following.
The US army has a number of histories devoted to supply or making supply requirements a big part of the history. The titles include two devoted entirely to the European Theatre of Operations supply situation, The logistics histories
Logistical Support of the Armies Volume I
Logistical Support of the Armies Volume II
The Quartermaster Corps,
Organization, Supply and Service Volume I
Organization, Supply and Service Volume II
Operations in the War Against Japan
Operations in the War Against Germany
The Transport Corps,
Responsibilities, Organisation and Operations
Movements, Training and Supply
Operations Overseas
For PoW treatment and casualty evacuation there are the medical histories, mainly The Medical Department: Medical Services in the European Theatre of Operations, they have a remarkable amount of aviation content.
In sorting though the various claims and quotes I am quite confident you could select the evidence to "prove"
1) The British were dragged kicking and screaming into Overlord by the US
2) The US was dragged kicking and screaming into Overlord by the British
3) The western allies were dragged kicking and screaming into Overlord by the USSR
Point 3 requires the most careful selection of "evidence". As for point 2 the US refused to give Overlord overriding priority in 1943 as the British requested, cut back on landing craft in early 1943 and until the end of 1943 had the priority for cargo to the China/India/Burma theatre higher than preshipment cargo to the UK.
The USAAF was trying to win the war through strategic bombing of industrial targets. The RAF was trying to win the war through de-housing of the Germans. By the time Patton made his breakout those objectives made no sense.
First Army created the break out as part of Operation Cobra on 25 July, Patton was not in command of any combat troops, he became an advisor on 27 of July and commander of troops in combat when 3rd Army was activated at noon on 1st August. The breakout was underway when Patton came onto the scene, he turned it into a potentially devastating pursuit by being prepared to take risks like being cut off and only having one open bridge.
By end July 1944 the majority of the air commanders had worked out they could not win the war alone, Bomber Command had reduced area bombing to around the same level as the 8th Air Force Marshalling yard attacks using H2X through complete or near complete cloud cover, poor weather attacks to keep the pressure up.
They shut off Patton's supplies because he was not following the agreed to plan of a "Dress Right Dress" march across France, all the Allied forces finally arriving at the border with Germany in JUNE 1945. Inertia Rules!
Who is they? Where did the supplies go to and what did the supplied units do as a result? Where inertia initially ruled was post breakout where the objectives remained the pre invasion capture of Brittany ports.
Around 2nd/3rd August General Wood, commander US 4th armoured division formulates his plan to turn east, but his request comes into corps HQ too late to affect his orders for the day. He has to wait until Rennes is captured. The commander VIII corps (Middleton) then permitted a compromise, drive south, not west, until the Chief of Staff of 3rd Army intervened and ordered 4th Armoured to go west. By the 7th Wood was at Lorient, but it was the 15th before he was released to go east. On 3rd August Bradley told Patton to minimise forces in Brittany, on the 4th Montgomery issued the go east orders. The Mortain counter attack started on the 7th.
During August 21st Army group loans 300 to 360 3, 6 and 10 ton trucks (6 or 7 above average capacity truck companies) to 12th Army Group, mainly used for 3rd Army supply. This loan is trucks as well as 3 to 4 UK truck companies.
On 16th September start of Red Lion run, 8 US truck companies (6 with 2.5 ton trucks, 2 with 10 ton semi trailers) to ship around 650 tons/day for a total of 18,000 tons for Market Garden, half these supplies are for the 82nd and 101st. The companies are withdrawn from the Red Ball Express and are replaced there by provisional companies using the men and trucks from the 26th, 95th and 104th divisions. The provisional companies are reported to be better performing than the standard companies. The British have responsibility for Red Lion route maintenance, supply loading and unloading, control of traffic and supplying the men and machines used. The US looks after vehicle maintenance. The route is very efficient thanks to denser cargo and the fact all cargo comes from the one dump near Caen to a single dump near Brussels, a distance of 300 miles. Each truck carries an average load of 5.9 tons.
In late September 12th Army group required 650 tons per divisional slice per day, plus 9th Air Force and advance communication section tonnage. It projected needs of 18,800 tons/day for 22 divisions in early October.
During the pursuit 21st Army Group's initial plan was for 7 supply routes. The roads in the area had been under maintained since 1940 but it was considered enough were first class. Instead it was soon discovered many of the roads were too narrow or too fragile to stand the traffic. US Red Ball routes had to be adjusted when roads were declared unrepairable.
As the US Army leaves Normandy it leaves behind over 2 million jerricans, which hampers the fuel distribution system.
There were numerous former Luftwaffe airfields in France that could have handled B-17's and B-24's
Why were the Luftwaffe building numerous airfields able to take aircraft bigger than what most of the Luftwaffe operated? And keeping them serviceable under the allied bombing?
Airlift to airfields in France would have helped that situation a great deal, at least relative to Patton's 3rd Army.
Why was 3rd Amy much better placed for large German airfields?
Patton wanted to close the gap at Falaise but was told not to. He was pissed at that.
Correct, there was a high chance of failure and he would be taking the supplies and troops that were being used to obtain bridgeheads over the Seine and capture other key objectives before the Germans could put defences in place. The Germans lost Falaise numbers of equipment and troops trying to get across the Seine before the allies arrived.
The US had never had an army group in combat. It came up with a cumbersome supply system.
As soon as sufficient territory had been gained 1st army would draw a rear boundary handing control of installations beyond that line to COMZ, the Communications Zone. Or more particularly ADSEC, the Advanced Section of COMZ, so there would be the army area, ADSEC area, COMZ area from front to rear. ADSEC would be a semi mobile organisation, keeping a minimum amount of rapid use supplies so as to be able to quickly move depots. One real source of friction was the head of COMZ, General Lee, was also deputy theatre commander, and while he was relived of this role shortly after the invasion the COMZ staff was also the ETOUSA staff, European Theatre Of Operations United States Army. This meant they were senior to the army groups, wearing ETOUSA hats and their equals when wearing COMZ hats. If there was a shortage ETOUSA would decide the allocation between COMZ and the Army Groups, in other words COMZ would decide. Since General Lee was an unpopular figure and gained a reputation with the armies for preferring appearance over substance any supply failures tended to generate even more heat.
On 1st August 1st Army finally drew a rear boundary and handed over control of the depots to around St Lo to ADSEC (COMZ), though it will continue to control some dumps for several more days. The COMZ HQ started to move to France in August, the office of chief Quartermaster ETO moving to Valognes. The change over date left very little time for the COMZ people to become familiar with the arrangements before things became frantic.
ADSEC stuck to the supply plan during the pursuit, opening depots that it stocked only to see them left well being the front line. By early September they had abandoned this plan, to assuming the pursuit was only temporarily paused, so hold off creating depots, an attitude that persisted through September.
One obvious example of the confusion was the units building the fuel pipelines having their transport taken away for a time to be used to haul supplies to the front.
Add caring for the civil populations, Paris had around 3 million people and needed special supply arrangements. The US was not able to put together a working supply system from the ports to the new front line plus care for all the civilians until weeks after the pursuit stopped at roughly the France Germany border, an area noted for its natural and man made defences.
There is a lot more in the histories. The US supply system was inexperienced and inevitably made mistakes, Third Army compounded the problems instead of easing them. The Overlord plan that had the armies arriving at the German border a year after D-Day was actually made for supply purposes. Any use, or planned soon use, of the paratroopers largely shut down the air supply system.
Cargo transported by air August and September 1944. Columns are week ending / to 12th Army Group / to 21st Army Group / to Paris. Supply in tons (unknown whether short or long, probably short)
26 Aug / 4,185 / 350 / 0
2 Sep / 1,877 / 917 / 1,676
9 Sep / 3,516 / 2,787 / 975
16 Sep / 3,221 / 3,712 / 0
Total / 12,799 / 7,766 / 2,631
Grand total 23,216 tons, 2,849 by the RAF 20,367 by the USAAF. In addition from 6 June to 19 August inclusive aircraft transported 14,213 tons to France.
8th Air Force supply flights to end September 1944, probably not included in the above.
246 Arnhem
245 Chartres
1,454 Lille/Vendeville
191 Operation Buick
319 Operation Cadillac
68 Operation Grassy
176 Operation Zebra
527 Orleans/Bricy
101 Warsaw
3,327 Total
12th Army group supply arrangements during September 1944. At start of month receiving 11,000 tons/day, of which 4,000 was for the air force. Daily allocations,
5th September 7,000 tons for ground troops 50:50 1st:3rd armies.
14th September as before but next 1,500 tons/day to 1st army.
21st September 3,500 tons to 3rd, 700 tons to 9th, rest to 1st (with a minimum of 5,000 tons)
27th September 5,400 tons for 1st, 3,100 to 3rd (1st had 10 divisions, 3rd had 8)