That number sounds way too high. Do you have a citation for it? The best estimate of actual post-WWII executions I can find is 486:
http://www.jewishvirtuallibrary.org/jsource/judaica/ejud_0002_0020_0_20618.html
"The total number of Nazi criminals convicted in the three Western occupation zones
between 1945 and 1949 was 5,025, of whom 806 were sentenced to death.
Four hundred eighty-six death sentences were carried out; the remainder were
commuted to prison terms of varying lengths."
I read the stat in a book called “Carnage and Culture” by Victor Davis Hansen.It does include German troops shot en masse in Russia after Soviet trials