Sounds like a good compromise, especially since most great cities, or even settlements, were built on certain strategic locations, that did not change much over time, other than with technological advancements and the discovery of certain resources, like minerals, or sometimes with great environmental changes. Paris and London were settlements long before they became great capitals. Stockholm, the capital of Sweden, is a fairly new city, less than 800 years old. Before it was founded as a proper settlement, "its province" was divided by the "provinces" of other settlements. The same is true with many other cities around the world, such as Warsaw in Poland, which was a insignificant town before the royal court was transferred there from Kraków, or Madrid, which shares a similar history.
The only question is how to do with those myriad cases where different settlements in the same region, "province", have switched places over the years, in terms of being the leading one. The history of ancient Mesopotamia and Egypt have endless cases of this, as has many other regions that have been civilised for many years. Should it be possible to change the "capital" of a province?
In any case, I think we can all agree that it would be best with a system in which the simulation itself changes matters depending on endogenous variables, such as culture and economy. New trade routes, new technology, new influences, leading to an insignificant town to become the leader of the entire region.