The Forgotten Battle

Filming the battle scenes in the Netherlands turned out to be near-impossible due to all kinds of environmental issues (certain wild animal populations that couldn't be disturbed, no permission for explosive effects, etc.). Another problem was that modern windmills had been placed around the original site of the titular battle, and money spent on digitally removing them would be better spent on adding planes or destroyed villages. The problem was solved by going to Lithuania, which offers tax benefits for movie productions. A piece of unused farmland was rented there from a farmer, who told production that they could do with it as they pleased. An entire dam was built there specifically for the battle scene.

The Airspeed AS.51 Horsa, the glider the characters crash in, carries up to 28 troops, 2 Jeep or similar vehicles, a single Jeep plus towed howitzer, other cargo, or a mix. There is no evidence the troops on board were associated with or made room for any cargo, or vehicles they could not recover, or any other reason there are some 20 troops missing, such as they were all killed, when they crash.