That’s an interesting system. Just thinking of Icelandic names, where it can get really difficult …
Anyway, I currently use the system “First name, middle initial, surname” but as you say, the first duplicates appear.
I have 4 folders currently, each with a separate TOC:

People get map locations (if they’re willing to share—just love visualizing where in the world I know people) and differently colored map markers for the four categories.
Simple YAML metadata looks like this:
location: [51.133333,10.416667]
mapmarker: Friends
nearby: 25 km
birthday: 1970-07-11
tags: friends
This can be picked up by Obsidian Leaflet maps, and also allows me using Dataview to show what or who is “nearby”, or when their next birthday will be.
Also, I have a set of links to Google Maps created, so I can easily click in a note to get a routing, and—in Google Maps—then send the route to my smartphone for navigation. Just one more click.
[[-Friends & Family TOC]] [[-Map]] `= elink("https://www.google.com/maps/search/?api=1&query=" + this.location[0] + "," + this.location[1], "Google Maps")` `= elink("https://www.google.com/maps/@?api=1&map_action=pano&viewpoint=" + this.location[0] + "," + this.location[1], "Street View")` `= elink("https://www.google.com/maps/dir/?api=1&dir_action=navigate&destination=" + this.location[0] + "," + this.location[1], "Route")`
(Each person note links to its TOC, the overall map, a Google Maps location, a Street View, and a Route.)
The (auto-generated from people, location & events notes) map looks like this:
(The lower “Nearby” map is created from an auto-updating note that shows my current location. Ideal not to miss anything while traveling.)