Is there any homebrew or variants that other fans have come up with to get in a 6th player?

Here is my idea for the Usurper 6th-player variant. I have not yet had a chance to test it, so please respond with your feedback to let me know what works well about it and what does not...

Introduction:
A new governor has joined the fold, and now there is unrest and distrust throughout the king's land. As governors vie for influence of the king's advisors, no one can trust that his newfound ally in the king's court will not be led away by another governor's guile. As a result, each governor must be cautious when approaching one of the king's advisors, or else he may find himself without the rewards to which he thought himself entitled.
Once a governor has revealed himself to be untrustworthy, the remaining governors become much more careful about ensuring that their own political intrigue will not go without reward. This governor's soldiers repay his cowardly act with an appropriate response of their own, by joining the victimized governor's army instead, thus increasing that chances that the disloyal governor may not be able to defend the king's land during the looming winter battle.

With the addition of the Usurper, a sixth player can now join a game of Kingsburg without overcrowding the game board with dice. The Usurper has the ability to effectively steal another player's reward from one of the king's advisors. This is done by replacing another player's die or group of dice with dice totaling that of the advisor in question. This ability can be used by any player in any productive season, but it can only be used once each season. Use any group of matching dice for the 6th player, most likely from another board game, making sure that the dice are easily distinguishable from other players' dice. These dice are used exactly the same as anyone else's dice. Also, make a copy of a building sheet and use whatever supplies necessary as a means of marking what buildings have been purchased for that player, since only 5 building sheets are provided with the game. Be creative.

Rules:
--Any player can choose to reveal himself as the Usurper in each productive season.
--A player removes an opponent's die or dice and places his own die or group of dice equaling the advisor's value (cannot be combined with the Market).
--If one die or a group of two dice was replaced, no matter how many dice the Usurper used, then the victim gains 1 soldier and the Usurper loses 1 soldier. If no soldier is available, then the Usurper loses one VP instead, but the victim still receives 1 soldier.
--If three or more dice were replaced, no matter how many dice the Usurper used, then the victim gains 1 soldier and 1 VP and the Usurper loses 1 soldier and 1 VP. If no soldier is available, then the Usurper loses 2 VP's instead, but the victim still gains 1 soldier and 1 VP.
--Only one Usurper can be revealed per productive season.
--Once the Usurper is revealed, that player cannot influence any other advisor during that season.
--The Usurper cannot be revealed in first round of influencing unless a player is replacing two or more of an opponent's dice.
--A player can replace a single die with two or more of dice that equal the same number (e.g., two 3's replacing a 6) or vice versa.
--If the king's envoy has been used to double-influence, then the Usurper chooses which player's die or group of dice is removed.
--The Usurper can use a +2 token if combined with one or more colored dice.
--The Usurper cannot use white dice, but a player can place white dice along with colored dice before revealing himself as the Usurper.
--If no Usurper was revealed during the productive season, then the lowest ranking player, as determined by that season's dice roll, gains 1 soldier.

Let me know what you guys think!!

I prefer the KISS method (KISS = "Keep It Simple Stupid")

Allow the sixth player to roll dice just like the other five. The only rule variant is this: (A very simple rule change to follow and understand)


This time, the player who goes last (the one who rolled the highest and is sixth in turn order) is the envy of all governers and has the attention of the advisors...

in this mode, the sixth player is just like any other player and EVERY player is eligible for the "envy bonus". The player who receives this "envy" bonus is decided based on the dice roll and the player who rolls the highest is rewarded for doing so.

This sixth player gets to double up on any advisor he chooses as often as he chooses. In other words, he is not restricted on which advisor he/she uses. It is a reward for going last and rolling the highest (and being the envy of others). This simple rule variant will keep the dice/advisor clutter to a minimum. I have playtested this and there really are very few glitches with this. It is no less troublesome than 5 players in terms of advisor collision.