>>64140060
a plane is vulnurable to small arms up to about 2,500 feet
what you gonna do, Have paratroopers be in the air for 2+ minutes? If there's a machine gun that can shoot at planes it also can shoot at paratroopers

also I doesn't say that all 8 Ju-52s lost were shot down by small arms, "Kampene i Norge 1940" which is quoted on wikipedia mentions that the cause of loss for two of the Ju-52s is unknown and that it is assumed that they crashed and sank, for the rest of the 6 it doesn't explicitly say it either