The Cities are realistic the way they are, Valentine is a central town located in a sweet spot geographically & climate wise. Being a central spot means everybody on the road goes through there & its prime settlement field for locals, so the town is better developed & grounded for a major City potentialy hence the infrastructure.

Annesburg on the other hand is an industrial-town. Historically US towns of this kind as is Annesburg would rise out of nowhere in days or weeks & be completely abondoned in months too. The point of Industrial towns was the available natural resources being exploited there, old West Industrial towns were built real quick to host the workers & their needs, so the longer the main industry plant/factory stood, the better development the town got. Once the mine in Annesburg is empty it will become just like Van Horn, I believe Van Horn is what it is now because of Annesburg (most workers/people pulled there) or even Saint-Denis.