Searching for 19th Century RN warrant officer uniforms for Dorward, I happened to find this site.
Very interesting, but I cannot agree with a number of statements:
(1) "The British and the Americans had the best NCO corps of World War II; the Soviets had the weakest."
What about the Wehrmacht?
(2) "Consequently, rather than simply accepting rank titles at face value, a reasonably approximate rank equivalency can only be established by considering what the holder of that rank actually did."
That sounds fair enought, but its never done consistently. If you equate a German Generalmajor with a Brigadier General, you also shold equate a German Hauptmann with a British Major, and a German Oberst with a British Brigadier.