Like some other WW2 battles, and many, many WW1 battles, bravado took the place of meticulous consideration, preparation and planning. The movie is not historically accurate, it was British and Canadian troops who carried out the ill fated mission and the British General Montgomery and his staff who championed it and planned it.
Planners were aware of, but chose to ignore the nearby encampment of the Waffen SS including an armored Panzer division, or the fact these were lead by a German general with a lot of experience dealing with paratroopers. The paratroopers were lightly armed and did not have the weapons to deal with the heavy armor of the Panzer division. Planners also did not consider the radios they provided to the paratroopers did not have sufficient range to be functional. Finally they grossly underestimated the time it would take supporting troops to reach them by ground.
Through operational errors paratroopers were dropped all over the place. Most within 25 miles of the target but none nearby. They then had to gather up and fight their way to the target bridge. Since they could not communicate with one another due to radio issues, they could not do this in an organized way.
Last edited by twowheels; 05-25-2015 at 09:11 PM.