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Should at least. I'm not even sure if it must necessarily be named English.xml or if it can be any name and must only be an XML with an appropriate header. At least it's not important at all how stat files are named because only the content is important. (Requirements.txt might be the only exception.)

I haven't looked at the other content of English.pak, but there might be some meta file which includes the current language and the engine then searches all XML file which have that language in some header tag.
This would give you the chance to put ALL language files into the Localization directory without other languages influencing the current selected language.

Although I'm no native english speaker I never played anything but english, so I have no experience how other language files look but there are tons of people who can tell you.
... or Abraxas knows since I know he's not native English either ;-)