So what if several SoE servers only really have the playermaterial to properly fill 2-3 regions, let them fill those, and let the players who want more space and care less of ranking play in the other regions.
Who says that the other play4ers care less about ranking? It may just be that they never get the chance to compete properly due to only have 50 people in the region compared to 100 in one city elsewhere.
There is also a lot of associations and players that better associations just don't want to have next to them, because they are negatively effecting just about every aspect of the game, and pre-regging in 5 assos in 1 region helps getting rid of some windowlickers.
Bigger does not mean better, I have seen some extremely good players in small associations, constantly beating many larger groups.
Why should you foist the 'windowlickers' as you call them on to other players, blocking all newcomers who are potentially going to be problems from interfering with your game but happy for them to spoilt it for others?
The diplomacy and building of relations for the next gameround is also a strategic element in the macro-level of the game.
On both the SoE servers where I have played for many rounds I have seen the power shift because new alliances were made, it's not so "given" or obvious that someone will "rule forever" as people think.
Current limits work fine.
I am on one of the same servers as you are and I agree that power does shift when players tire of the game or look to move as a group, however it is very difficult to build up sufficient power to challenge them if all of the top associations stay together.