WWII=Axis vs. Allies
You want to fight Brits, Russkies and Amis--->SH3 (Means u-boats of the Kriegsmarine)
You want to fight Japs--->SH4 (USN boats)
Notwithstanding the Atlantic Wolves mod you don't use u-boats to sink Germany's Ally.
Simple really.
Maybe our Chinese member should play DW and sink some modern JSDF subs if he doesn't want to play USN in WWII.