This idea would not encourage the vast amount of crappy players out there to play. It seems that most games 80% of the kills (and most likely damage as well) are done by the the top 2 or 3 players on each team. This would mean 80% of the wealth would go to 5% of the players. Medievally realistic but not much fun. Then too we will hear a lot of forum rage against cav and head shotting range, because although it sucks now being the first one being randomly killed in the charge it would be very angrifying to know you're losing out on cash and exp because of your bravery.
As for team work, it might not kill it but it would maim it into something gawdawful aberration of nature. It's bad enough with guys charging at unshielded 2 hander guys out in the open without letting archers/throwers 'soften' them up first (especially on bridges!), or leaving the protective umbrella of ranged on a rooftop to chase a peasant down for the easy kill, losing that 'arrow in the back of the head whilst dueling' advantage, plus leaving the enemy access to the archer's ladders. Needless to say TKing TWing will increase ten fold.
As a useless player who can't hit the broad side of castle with a broad axe, I still believe I do my part. I try draw enemy into our archer's fire (and turn them so thier backs are exposed), I try set up enemies when I see cav charging behind me, I circle round dueling guys to distract and dismay (until they recognize my char and ignore me).
All those 0 kills and 6 deaths people do something, even if is just to give better players the satisfaction of chopping them in half. Stop paying them and they'll (ok, ok, we'll) stop playing and then you might as well just play on the duel server.