Explanations/etymology also appreciated!
For Joe Shmoe, it means a very average or below average person. It’s a derivation of the practice of using “shm-” to dismiss something (eg “Practice shmactice. We’re already perfect”).
And “John Smith” is meant to be the most average name or person imaginable, so they have the “most common” (citation needed) first and last name as well.
Does this came from arabic influence?
To refer someone without a name or generic name we sometime say Fulan bin Fulan meaning someone the son of someone