Interesting. My estimation above (turn-around times for a double drop) are not totally wild guesses, I used to work as ramp agent during my studies, so I know what's possible, from a technical PoV. While modern loading + boarding (of large civilian planes) require a lot more infrastructure/effort nowadays, parking, refueling, loading and lining up again still required a concerted effort on the apron back then, already (just think about the number of petrol tankers that had to be employed or the time needed to attach new gliders - which could be stretched, though, as the returning planes didn't come in at once) - my estimation assumed that well trained ground crews and tankers were available in numbers. I thought that wasn't too far-fetched, since the RAF had organized the first "1,000 bomber attack" during Operation Millenium as early as May 1942 (night of May 30/31), and as the RAF had collected more experiences during the subsequent and similarly sized (2) raids on Bremen and Essen. The high degree of organization (and revised flight formations) reduced the TOT (time over target) to 90 minutes (even to 20 mins. later on) for the entire bomber force. The RAF collected a lot of information/experiences during Millenium, and the experiences gained then heavily influenced several types of large-scale operations, including the launch and formation of transport armadas. Imho, the refusal of double-towing, and the missing imagination (lack of mental flexibility) in the leadership that say at least 2 weeks of training/testing for double-towing could have established a better (informed) base for a decision, deprived Gavin's unit and the Paras near Arnheim of vital fire power. If I am not mistaken, 2 vital AT guns didn't make it to Frost's group, because the particular glider crashed (?). Double-towing gliders could have enabled the troops to compensate such losses with additional/backup EQ. The double-tow training was then ordered for Op. Varsity. There was a lot of bad luck involved, but the whole OP was tailored around a risky/ambitious/bugged plan, where then the decisions of some leaders (in HQs in the UK and on the ground in the NL) hampered the ill-fated plan even more, imho.