While browsing the CARL WWII documents I came across this summary of glider operations for the 101st Abn Div in MARKET-GARDEN. 101st Airborne Division Operation Market Garden. :: World War II Operational Documents I excerpted the FA for D+2 because it gives some round numbers for air lifting the glider FA. The numbers for the 321st GFAB seem complete and consistent with other sources. The numbers for the 907th GFAB has a significant gap in the personnel categories that make it less reliable but it might provide an upper limit for the number of gliders. The total of 71 gliders seems low unless a glider could carry both a jeep and trailer or a jeep and 75mm PH. Assuming many of the trailers came loaded with ammunition for the howitzers, I still wonder if they had any additional gliders for ammunition or could they rely on later re-supply. While it seems to be a period document I would not rule out the possibility of errors.
Maybe you already saw this thread/topic on this forum. I know I don't search this forum enough for related topics. http://www.ww2f.com/topic/32447-17th-airborne-194th-gir/