Well it makes sense for a historical leader to make laws based on their own values and then for the civilization to follow the rules set forth by the original leader. Confucius, Mohammed, Odin, etc are considered the ideal rulers from their respective cultures. More recent figures like George Washington or Ieyasu Tokugawa created nations based on their own ideals.
However, as a game, I'm not completely comfortable giving the keys to the entity car over to the computer's RNG. I would miss having the ability to jump into the raws and fine tune a civilization to be exactly what I want.
Yes it does make sense for them to have an influence. It does not make sense however for them to be able to conjure up entities/nations based upon nothing else but their own personal views on things. George Washington and Ieyasu Tojugawa may have an influence on the development of America and Japan but neither of them were able to simply invent nations, the nations instead can equally be said to have invented them (hence Odin in your post, who is not exactly a historical person). Mechanically however, trying to figure out how to realistically have ethics/values change over time based upon the agency of individuals is pretty hard to figure out and inherantly politically charged.
Thing is that individual rulers cannot simply dictate their values to the people, most of the time they are either rulers because they happen to share the existing values of the people somewhat or they have to conceal their divergant views in order to become/remain rulers. At the same time it is clear that change cannot simply come from 'the people' because the majority of people invariably agree with the majority view on a topic there is no reason why the majority view would ever change. The main problem with the present setup is that while particular individuals have fixed divergence from the ethics of their civilization on a few points, there is no representation of the difference between fixed and malleable views which is essential if this is to work.
An individual has a number of fixed views, which may or may not correspond to the present civilization consensus and on all other views he automatically agrees with his civilization. We take all historical characters fixed views and we periodically adjust the values of the whole civilization towards the average of all historical characters with fixed views on a given subject. We also weight all position holders with [LAW_MAKING] token by making them count as the total number of historical characters that belong to their government, irrespective of whether they agree with them. Rulers of more populous sites have more influence and civ-level rulers have more influence than site level rulers.
The question is how to manage rebellions (higher level positions being removed by subordinates) and purges (subordinates being removed by ordinates for ideological reasons) in this system. The way I would do that is to have the value adjustment happen gradually over a random period of uncertainty to it's new value. During this period we test all the holders of [LAW_MAKING] positions against the present value, those who have fixed opinions on a subject that is being adjusted opposed to the present 'way things are going' are at risk of being overthrown. For a rebellion to happen there must be a historical character belonging to their government that agrees with the new values more than they do, for a rebellion to fail there must be a historical character belonging to their government that also disagrees with the 'way things are going'. The more rebels there are vs loyalists the greater the chance of the rebellions succeeding, if the rebellion suceeds then one of the rebel historical characters siezes the office and all existing positions appointed by that office are voided. If the rebellion fails then the historical characters in question get punished (or not) according to their societies ethics on treason.
Purges are simpler. If the holder of an appointed office holds a fixed value that disagrees with the appointing office holders values, fixed or otherwise then they can get dismissed from office and replaced with someone that agrees with the appointers values, if one if available. This can happen at any time, unlike with rebellions which can only happen if values are presently shifting, but when things are fixed then a purge cannot happen unless the ruler has a fixed value opposed to that of the holder of the appointed office.