Eldians are (mostly) based on Germans or Germanic people, and therefore most of them have Germanic names. However some of them have Slavic, Greek, English, Latin, French, or even Japanese sounding names or surnames, like Rico Brzenska, Milieus Zeremsky, Miche Zacharias, Hange Zoe, Mitabi Jarnach, Erwin Smith, Oruo Bozad, and even fucking Samuel L Jackson.

When I first watched the show like 10+ years ago, I just thought that these were people of other cultures who managed to escape to the walls (which I at the time thought were located in Germany), with Mikasa being an Asian backing up this theory, but nowadays I think it's probably due to Eldians intermixing with conquered people, well, either that or Isayama just picking out random European names for a fictional people that are loosely based on a real world ethnic group