I guess if it was optional, then it could work.

Maybe they could implement a command "/display surname off"

This way, for all intents and purposes, you would only have one name. Even though technically (according to the server database) you actually had two names.

The issue of course would still persist for sending tells to people. And also there would be a possibility of running into two people with the same first name, both with /display surname set to off.

Okay so basically this idea doesn't work.