Well by the 40's many US press photographers were using 35mm and 6x6 cameras. Not all used Speed Graphics some used reflex grahics,

In Europe the 9x12 Avus style cameras were the norm befrore WWIIwith some SLR's as well, the UK was similar but cameras like the Sanderso were more common and therre were light weight press Reflex cameras like the Press Dallmeyer with faxt lenses. Smaller formats took over during the war.