First.. I am p!ss-poor in a fighter...
Nevertheless, I'm not that desperate to get a kill. Could care less whether I get it or just assist. Sometimes I would just play "bait" to help the other guy knock down the opponent. If I can help a fellow "countryman" get his kill, I'm just as gratified I helped out.
There have been times I've jumped in at the request of a fellow player, and while he may have his opponent in his sights, taken parts off the guy, and yet I end up with the "Kill" message.. it doesn't seem right.
Sportsmanship matters regardless of the game being played, whether you're sitting at the same table or on different continents.