The only 3 clans I've noticed are EKT, TMX, and JTEK (I believe this is a clan?). EKT and TMX are more communities than clans now, really though.
I'm trying to build a competitive clan, with hopes that the game does become vastly more popular in the future with a steam greenlight or origin release. This means that I do very much so intend to deny players who I do not see as adequately skilled enough. Good personality and values are certainly something I look for, but skill is the primary recruiting and application factor I will be using.
I have been the owner/co-owner of a few Renegade clans back in the day, as well as being in over 10 total through my 13 years. I am very serious about this clan, and I'd rather have 3 skilled members than 20 average members. With that in mind, I cannot say a minimum recruit number. Back in the cw.cc days, a competitive clan would have 4-5 main members, and then any others would act as as a bot (playing on the same nickname, such as WaRxBot for competitively logged games). I intend to build with the same structure, but just figure out the bot situation later, since there currently is no real "competitive play" in the game yet (beta and all).
I'm looking into recruiting some players that I played with in Renegade that were very skilled at that game, and who I believe could make a quick and powerful transition. Currently we have 2 members (myself and 1 other with a very different timezone), and so we are looking to expand. However, I will gladly be patient and wait for true talent; rather than accept or recruit people who I don't consider competitive play material.
Skilled casual players is the player-base right now that I'd be recruiting from in Renegade X, which is a good start considering that this is beta. I'd welcome your application gladly.