I am part of ZXD and we play Squad every night together as mates on public servers.
Theres a couple of things to consider, first off what is a clan server over say a community server. Most of what we play on are what I would term community servers. The RIP vs the world Friday night event is a good example of a stacked clan server (and its usually a great night gaming).
We generally find with a full ZXD Infrantry Squad and supporting single heavy vehicle, if all the other side is public players we smash it. If there is another clan or 2 full Squad/s on the other side it can be a good, close game and sometimes we will even lose.
I feel its the admin that makes the difference, and then the Squad Leaders. I have literally played dozens of round where the opposition will simply not bother to cap initial points and then wonder why they lost so bad. Or set up half sensible spawn points, or heal each other or, well do much at all except run and gun. So many rounds our Squad Leaders report that the (often) public Squad Leaders don't say a word about the round............................like nothing at all.
So my choice is simple, play with the public all the time and I recon have maybe a decent round in every 10, or do what we do and have a 7 decent rounds in 10.
Alot of people feel or express a clan is some mystical crazy set up, it often isnt. We just play Squad (together) every night and love the game with a focus on team play and winning. A little try hard but hardly off the scale! The result is over many thousdands of hours, were a pretty good team and win way more than we lose.
That can upset public players, and for that, we are sorry..............................but hey get on and gut good right!
So my point is or the most part my experience is that clans, and indeed clan servers are giving our public players the oppertunity to play the game well!