I originally wrote a couple short pieces for Heavy Magic and had the same basic ideas that I'm expanding with the 30 Days of World Building.
One thing that I thought about as I was thinking over those original pieces was that I never intended the Fidchin and the Golchin to be different races, more like different classes.
I'm not sure how to annotate that to stress that they are really the same race. I kind of moved them closer by giving them the same language, with accents.
The desert people on Wispollil are a different race as are the Fjordlanders, but they are all much more closely related, being descended from the alien settlers and not of native stock like the people of the Great Old Empire.
I don't think I'm going to go back to the other posts, but let this be enough of a note and continue to treat them in further posts like they are part of the same race.