Let me put it simply for you who seek a Scandinavian guild... there is most likely going to be 1-3 of those guilds as they have been there on both K1 & K2 however if you want my opinion it is better to be more broadminded rather than exclude potential friends.
If you exclusively go for a language/country based guild you will be playing with a much more limited crew, of course Scandinavians are world wide known to be among the #1 most friendly & happy people but still if you are neutral and speak english not only will your english improve you might meet people you otherwise might have missed and it feels more coordinated & professional to communicate in english ^^
Population might not be sky high but it will never be dry, heck even when rival servers tried to proclaim kronos dead or inferior numbers didnt drop instead after some time those so called rivals died out instead, i am sure you can find some youtube vids left from the time when people tried to do so still ^^
If you want a more valid picture then take a look at the raid logs as you can track guilds performance & rankings back to release if you wanted or just read through the nice visual display to get an idea of how well the raid performed or the individuals ^^
you should take a look at those logs & the armory there are quite a lot of neat stuff