The `World > Continent > Country` classification is not very fine grained

[Jorropo]

I find something like World > Continent > Sub Continent > Country is more meaning full, example with stats provided by the apnic:
https://stats.labs.apnic.net/ipv6/

I can get you a .json file of some arbitrary but probably usefull clusters (such as ones used by the apnic) if you are up to implement this. 🙂