And in the case where someone has the exact same main and Legacy name? or has no legacy name? or perhaps you're trying to send it someone that chooses not to display their Legacy.
Like I said above, there can only be one John Smith per server, but there can be another player by the name of Joe Smith, or John Doe etc
Pirates of the Burning Sea has a similar naming design and it works perfectly, if you don't want to reveal your legacy name from sight that's fine, but in order to send a message you need their legacy to clarify that name.