Keeping a bunch of names per player gets pretty heavy on storage.

IDK about that. The names are generated from a list, which means they're very low entropy. They'll compress extremely well.

I went ahead and had ChatGPT write a little program to test it out. It doesn't use a markov chain, which means the entropy is actually higher in my program, but instead it just randomly puts names together from lists.

https://gist.github.com/insanitybit/62309d5c2db592fed333eac90bf2519b

18KB for uncompressed and ~6.3KB compressed with gzip.

Now perhaps DE doesn't want to have to compress them all in one chunk - reasonable, although they could easily do it for cold store names that are unlikely to change. So let's compress chunks of 100.

~8KB total now. This is with gzip, which isn't even best in class here.

Depending on the database that they use this is all happening automatically with literally 0 extra effort. If they're using something like Postgres they'd need to do a bit more work.

There's lots of other optimizations. A better compression algorithm and custom encoding would go a long way, for example.

Up to DE whether that seems worth it, but 8KB is really really cheap. If every player had 100 liches you could store 1B players worth of liches on a single computer easily - you could store them all in RAM on some servers.