As long as the Servers are divided by time-zone, NA vs EU, there is always going to be a strong inclination for server populations to be time-zone centric.
As it stands now, GW2 is designed this way.
If servers need to be grouped, the basic solution I would start with is simply renaming those groups. Encouraging new players to join either server group would eventually (1-2 yrs) help provide a longer term solution to “coverage wars”.
5 Shades of Grey
“Give up, I’ve got you surrounded”