This system isn't very popular, most guilds avoid total wars at any cost.
However, someone proposed extending this system to individual kills. I was also thinking of something similar a while ago, but my main concern was cheating (someone creating an alt so that he can kill that alt and gain points, or have a friend's alt do that).
Today, I think I came up with a solution to this problem. Not a perfect solution, but it should solve most of the cheating problems: Only the players with a relatively high attack and defense rating would be able to participate in such a system. So if you attack and kill a newbie, or if a newbie attacks and kills you, no one gains or loses a point. Besides, leveling an alt to a very high level, just so that you can gain points with it is impractical; you can use that time to actually level your main char and get more points.
As a failsafe, we will monitor suspicious fights, and if we determine that someone is cheating, he will lose all the points.
There are two possible systems we can implement: Symetric and asymmetric.
The symetric system is the easiest: You lose a fight, you lose a point, you win a fight, you gain a point. This way, the sum of all the points in the game is close to 0, but not necesarly 0 (for example, if someone destroys their character, or if someone is punished with a points reduction).
The asymmetric system differentiates between combatants. If you kill someone of a lower level than you, you get little points, and the opponent loses few points. If you kill someone of a higher level, you gain more points and the opponent loses more points. Determining the levels of the players is tricky, some suggested to use the number of points each combatant has, and implement something close to the ELO Rating System. Another way would be using their skills and attributes as a level. Both methods have various shortcomings, and I will ask the players which system they would like most.