Are we really certain that clans are a collective thought? I have been in a few clans and the ranges of game types, competition, etc may be evident with several well-known ones, but for the most part they are just a group of close friends that play together. There is not necessarily a single "voice" of each.
The most obvious to me is a clan that has a country of origin, sentons-only, or a casual one. There are VERY few that are competitive-based.
SA clan = competitive 1v1 just like the majority of members who were lifted from BAW
ZFG = zero-fucks given, just a casual clan that happens to have some competitive players
SNF = not really sure how to describe them as there are so many, but for the most part seems like a mix of everything
EDC = now disbanded
ONI = not that active anymore? When I was in it, they were 90% very casual spare a few competitive players like AchievedJaguar. For the most part it seemed like a group of Brink following (not a bad thing, just saying)
GB = mostly inactive, but was for the longest time a group of casual UK-based players, grew to have some of the better players in the community
JEW = mostly sentons
SC = Sentons chat mostly sentons
ANZ = collection of Australian-based players
PLD = I believe this one is mostly Russian-based
SCR = mostly disbanded but same concept as PLD?
JoP = competitive, high-level players with some VERY active and mostly inactive players
These are just to name a few, but the other less-knowns are really just casual players that just come to enjoy AI games, custom games, etc. I don't see all that many as vocal as the ones aforementioned.
Perhaps some clan reps could weigh in and say "This is what our clan is all about."