Can't add much to what Ghosth said, but I will say that getting separated or even being with the friendlies but in poor position is like being a young wildebeest in Africa away from the heard and the lions are on the hunt. They WILL come after you.
It takes time, but when you go through a large formation you can pick out the guys that are 'just not quite as with it' as maybe they should be. They are often toward the rear to the center. Not usually in the front, and sometimes in the outer edges. Generally in a merge with a group I can quickly spot an easy kill or two. Other squads have guys like me that also look for the 'one or two guys' out of position that are not acting or reacting like they should. You don't want to be the one they are after. One of the best ways to do that is to go after them, but don't put yourself in a position to let someone saddle up on you. This is easier said than done Flushed. It take time. I know it can be frustrating.
Winging with someone really helps. In the Pearl Harbor event last night I knew Kansas was watching my back. That really helps. In the squad duel last Sunday night when Ghosth and I were fighting against 3 we really covered each other there and it made the difference. Not to take anything from Ghosth and I, thankfully those three did not really have their act together, but it shows that a little bit of wingman tactics, and communicating can over come superior numbers. (forgot to save my film from that squad duel, grrrrr!

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My suggestions:
1. Make a real effort to stay with the pack. I generally let you guys know when I am turning one way or another.
2. Be aggressive with your wingman. Look for those young wildebeest's.
3. If you don't see an enemy then look for the largest group of friendly's and head toward them.