Ancient Era is my open standard term to what would be Low Tech Eras in GURPS. I admit its not very accurate, but so is Low-tech, but it will do for an open standard. AE is used for short in this document.
I have been mulling over this in several days, probably two to three weeks. I've experimented in organizing AE Professions by Service vs Producers; Urban vs Rural; and Management vs Workers. All are important in describing and organizing these professions and putting down assumptions so that people can easily know where they can easily make alterations and where are the implied exceptions.
Before I get to what I figured out, first I have to provide some requirements as to how best such is organized. One important thing a World Builder needs is the ability to create socieites easily and all the necessary bare bones technical Infrastrcuture, basically from the simplest societies to societies that increase in complexity. A GM can build a household of a noble, that is the key management center of a village (if the family is a small man-at-arms family or sergeant: village manager family). As the GM paints a more detailed picture he can proceed to describe the economic specializatin and non-essential trades and products of the economic unit.
So by now you realize what organization I've fallen on to by having narrowed the paramters by what is essential, to what is opportunties oppened up by specialization, and allowing for templates that can apply across multiple Eras and Cultures. The basis AE professions are: complexity and technology.
How this works is we start with the simplest and most common set of professions to run subsitance level of survival for a community. As food becomes more plentiful, more opportunities open up; allowing for complex but worthwhile products and services AE people would trade for. If we follow this method what we have is branching trees of services/products. The branches are thicker when more people engage in the activity and the thinest branch is very few people do engage on the activity.
Then imagine layers, like GIMP or Photoshop Layers, we can use the layers to imagine different evolutions of technology. Where some layers have trunks and branches that are narrower but have more branchations as technology improves. The older AEs are thicker trunks but few branches, the later AEs have slightly narrower trunks but more branches. The branches themselves have complex relationships, which will be a foot note for now.
The best way I can do this is having either a spreadsheet map it, using colors to represent the thicker trunk of food producers, moving towards the branching elements of specializations. One sheet for the “tree” and one sheet for the list with its elments. So Two sheets per Major techological breakthrough in AE particulary in food production. Empires come into the Picture, is when they start having economic specialization in regions like when the Tang and the Romans made breadbasket regions and used water ways for logistics.
Wow, that is a lot of work ahead. But again, its an open system, I break ground here its easier for world builders to make settings in Sumaria, Ancient India, China etc.