SE should try balance the regional IPs for each server.
For instance balance the server with 33%JP 33%NA 33%EU with max players at 2,000. Which would give prime time for said region about 660 players.

When transferring suggest the server the player should transfer to to balance the number, but allow the player to choose any server regardless.

This way the servers will have players at all times of the day without too much dead time. (loading a server with 70% EU players would impact non EU players on said server)

This would protect the server from being language dependent or time zone dependent.