Merging servers is an extremely unfortunate but also common process throughout the life of many MMOs. It's just something that eventually has to happen.
Taking a look back at several other games in the genre, I would like to point out how each of these handled the issue of underpopulated servers, hopefully this proves just how nonsensical and overly complicated the currently proposed system is.
Game: Everquest
System used: Each underpopulated world was merged into a more populated server. The result was a server named with both of the previous server's names.
Example: Server Stromm was merged into server Luclin, becoming thus Stromm-Luclin.
Source
Game: FINAL FANTASY XI
System used: "Characters from the "Source Worlds" will be migrated automatically to the "Destination Worlds."
Example: Ramuh ->?Bahamut
Source
Game: TERA (JP Version)
System used: Groups of servers (3 at a time) were merged into a single server
Source
Game: Rift
System used: Players are given a suggested server to join but are free to join a different one if they wish
Source
See the pattern here? These are all standardized and acceptable ways to deal with underpopulated servers.
So why, why are you going out of your way to make this as much of a problem as possible? Why are we forced to divide communities and split because you're don't want to name the new servers and or give us a manageable system like every other MMO has done in the past... including your own?