I don't see how this would be a bad idea. Give no bonus from TKs (duh, the devs aren't complete idiots). If it's possible give the reward to the person who did the most damage, do that. If you have x1, the reward is 5k, x2 4k, etc. etc. Give a reduced bonus on siege, maybe 20-30%, as peasants are numerous. While I'm thinking about peasants, give no reward for kills against players who are under level 20.