There's this one US Army staff officer from the 1930's and 1940's I've seen mentioned in a few bios of generals like MacArthur and Marshall. Guy by the name of Eisenhower. By all accounts a very intelligent and brilliant master of organization, but somehow never broke into a command or field position during WW2. Retired after the war in 1946, and wrote a well regarded history of the Civil War battle of Gettysburg which was published in the early 1950's, though.
WI we make Eisenhower President instead of Dewey?