Think about this your a king you have 6 guards and 2 kills, and an alchemist on you. You feel so confident that the only way you are going to die is by being lynched. No Unseen nor NK is going to kill you at nights. The King is chilling.
This situation needs to change. I think every king should have 4 guards, but the starting king gets 2 kills in addition to those guards. I think this for multiple reasons. The first is that as King it takes no skill to survive the night. There is either an alchemist on you, or you have 6 guards otherwise to protect yourself and just relax and feel no pressure. By giving King 4 guards (as it was) allows the king to strategically plan what night to guard. Whether he feels threatened by the Unseen or the possessor might possess him etc. Another reason is that this change would help NK wins. The King has to be either good or evil. As a result, the king will never side with the NK. Furthermore, this means that for the Neutral Killer to win he must kill the king at some point. And with 6 guards and some healers no NK unless empower reap will king the king. This is shown in the TOL IV tournament where sorcerer and poss have 0% win rate and reaper had a 16% chance because reaper can kill king. So this change would help those NK win rates. Where they were so low as before.
Unseen will attack the king less because there is a 35% chance that he is evil which allows the king to have less protection. Therefore having 4 guards is appropriate.
