
On the Plarium server, it's a little hard to tell. I'm not sure how many new players are joining and STAYING.
Currently there is a very well defined top 10 clans- Almost all of which have been top ten for YEARS. (I have played for nearly 10 years exactly) and include both real players and alternate accounts.
With the amount of time that has passed, each clan has built up a (basically) un-attackable amount of defense, and thus are all generally at a stalemate. Not that things can't change, and no doubt will, eventually...
Getting into these clans will probably take at LEAST 100 billion of your defense on emitters.
The REAL wild card are the 'bot clans' (Clans built of botted alts) that may or may not be silently stacking billions, if not working towards trillions worth of offense and/or defense.
I have been out of the game for months at a time here and there, and have well and truly been out-of-the-loop when it comes to smaller clans and their activity, so I cannot say how active the smaller clans are.
Large, certainly have corrospondence between Deputy clan leaders/clan leaders, however. (these players have been playing with eachother, as leaders, for YEARS), and almost certainly have corrospondance with their allied clans, or clans during conflic tornaments.