As a general rule, if there's a crowd chasing some Dilbert, I just watch in amusement. If the Dilbert turns towards me, all bets are off. Otherwise they can have their fun.
However, when the shoe is on the other foot, these same pack dogs will barge into anyone's fight uninvited. When I spot a recognized kill stealin' weenie, I'll pick his thieving pocket in a heartbeat and leave him huffing and puffing and spewing venom.
There are fun ways to deal with those greedy characters who shoot over one's shoulder too.
Last tour I flew the A-20 as a fighter quite a bit. I was tangling with a 109 who tried to BnZ me (the silly boy), and after about three minutes I was just about on his tail when a pair of fellow Rookdorks tried to reap the rewards of my hard work. A 190 and La-7 dive in behind and start shooting over my shoulder. I simply tightened my turn and pulled into their tracers, then drilled the hapless 109. As I pulled off the dying 109, I had the reassuring view of two chutes drifting down to the ground. It just doesn't get better than that. The pissing and moaning was epic. What was really funny was that because the killshootered Rooks both bailed, the 109 driver rode it in and got credit for both kills!!!
My regards,
Widewing