MountainMan,
I'm going to disagree with you on this. Fact is, no clan worth their salt as people feels the need to go stack against what is essentially a loose scrim game.
1) They learn nothing from it, since the other side isn't employing any real strategy, and any tactics they do use are of convenience. As often as not they are lone wolfing, and really easy fodder for a two or three man team.
2) They have bots who can be set to be more dangerous than ANY human for practicing reflexes.
It's like a pro hockey team (or semi-pro) taking on a group of people out for a simple scrim. They (the semi-pros) get nothing from the experience except the satisfaction of defeating people who aren't even aware they're playing semi-pros. The people just trying to have a fun scrim get their game ruined and get absolutely nothing out of it except frustration and anger.
I'm not "honored" by any clan visiting the server, I don't care who they are. DC and BF42 are GAMES. I am impressed by a few clans who visit and play with ethics and split teams, and act as ambassadors for their group. But I am not honored to be in their presence. It's our server, not theirs. Our house, not theirs.
I think the best suggestion is to put a "No Clan Stacking" rule into play. Real clans or gaming groups should have no problem with that. Those who do aren't honoring the spirit of the game, and I'll happily show them my boot.
The SG server is becoming known for good play.. it gets busier sooner and the numbers of users are growing. That's not because of any clan or gaming group. It's because we (as a group) play with a sense of humor (most of the time.

), are in it for the FUN instead of being hyper competitive, and have Admins who care abotu the rules, follow the rules themselves, and will enforce the rules. (Not that we don't make mistakes, I know I do.)
It is THEIR honor to play on OUR server.
YMMV.
Regards,
-Bouncer-