I must concur with the opinions expressed by the OP. The system that is inplace in FFXI would be the optimum way to go. That is the group that claimed the MOB has exclusive rights to that mob until they either kil it or lose hate for what ever reason. The only concern with that is people who hold mobs til they can gather suffienct forces to kill it. Checks must be put in place to prevent this from going on for more then 5 minutes.