This is a common issue in all communities. It's also a very sensitive topic. Everyone wants to play with their friends. It just makes the game more fun. But without non-eGO members, the servers don't stay full of people to play with and that's no fun either. If there was a simple answer, I'm sure leadership would have implemented it already.
My takeaway from Tomain's OP is this:
"On our servers, the only way we can encourage fun and respect is by LEADING BY EXAMPLE."
eGO members should be mature enough to self-regulate, without the need of a server plugin, and to recognize if team-stacking (intentional or otherwise) is reaching a point where it's making the server less fun for others to play on.
My personal rule on this sort of thing is that if an issue is severe enough that it's causing multiple people to leave a server, then some adjustments need to be made. But it's a personal responsibility. Will you be the person to initiate or add your vote to a team-scramble? Will you be the person (or people) to willingly switch to the weaker team to show good morale? And if you're rolling a team of pubbies with your eGO buds, are you gloating and smack-talking or are you being a good sport, saying "GG" and "Good try" and encouraging the other team to keep trying? A good attitude can make all the difference.
No one can enforce a rule to make people do that. There's no plugin or addon that creates that. This comes from a personal choice we each have to make when we are placed in the situation. If I'm ever in doubt, I ask myself "Is this helping bring fun to the server or just fun for me?"