The typical use in English of placeholder names for persons is to emphasise their random selection, or their representativeness. Hence the rich assortment of List of terms related to an average person, including J. Random Hacker for computing, Tommy Atkins for the British Army, or The man on the Clapham omnibus for the legal system.
Going through the Wikipedia language list for all the following:
- Dutch makes a class distincion between the average couple Mieke en Janneke, and the lower class average young couple Sjonnie en Anita. That’s easy to replicate in the various dialects of English, with whatever given names happen to be in vogue in a particular community.
- Hebrew has Buzaglo for a simple lower-class citizen (a Moroccan Jewish surname, reflecting the lower status of Mizrahi Jews).
- Finnish has Pihtiputaan mummo (“the grandmother from Pihtipudas”) for someone who’s the last to adopt new technology. Again, I’m sure other languages have equivalents. Ditto French Madame Michu as an unsophisticated computer user.
- Hungarian Gizike and Mancika are “stereotypically obnoxious and ineffective female bureaucrats”. (This sounds like Patty and Selma from the Simpsons.)
- Legal Latin as codified by Justinian used Titius and Seius as names for Roman citizens, and Stichus and Pamphilus as names for slaves.
- In Portuguese, João Ninguém or Zé Ninguém (Jack Nobody) are used for someone who is unimportant.
- In Russian, Dzhamshut is a derogative placeholder for a gastarbeiter from southern Former Soviet countries.
- In Tagalog, Hudas (= Judas Iscariot) is a placeholder for people the speaker considers to be a malefactor or treacherous.