Personally, I pretty much agree with the people that say you should have equal skill on each team. It is no fun to get decimated time after time.
Those that say it is nicer to play together with those you know are right, of course. But then, it's also fun (maybe even more fun) to beat those you know. (Right, Blake? :twisted

And in a way, I find it fun as well as rewarding to help those new to the mod find their way around. It may be a little harder to co-operate with people you don't know, but that doesn't mean you can't try. And eventually, you'll get used to those people too.
If you are used to playing with two or three others on the same team, well, you could also take your friends and join the other team together. Form a squad, invite some new guys, and you can still play together and at the same time you can help others to get the same fun out of the game as you do.