in addition, the size of the units is the same between the 1941,1942 and 1940 versions?
The units in 1941, 1942, and 1940 are all roughly the same size between editions:
US Sherman tank in 1942 and 1940 are the exact same size. US IS-1 tank in 1941 is a little bigger than the US Sherman from 1942 or 1940. All of the US Infantry between 1941, 1942, and 1940 are the same size.
Does this answer your question?
-Midnight_Reaper