Darkodinplus-I really like that.
Frogboy -To me it would be a great way to add 'life' to each and every hamlet, village, etc. It is also a little bit 'sim' like you say, however, couldn't you just abstract or make a few animations/still works to imply you have 'all these' working people. The cities are yet to be changed to make unique/fun/active/interactive.
Tasunke-I believe just the opposite. That to me echoes 'real' life. What I do for a living(sometimes, cough, cough) is build stuff. Houses, Schools, Transit District Depots, Multi-storied parking structures, etc From real elaborate to hatchet job. Real big expensive projects and for people who can barely pay at all. I've been the ditch digger, garbage pick-up guy to laying out large buildings and structures. I've learned a little bit about residential and commercial concrete, tiling, masonry, plumbing, electrical, carpentry. I'm definitely not the best at what I do.
I've done a lot of other things to in my life(school, military, security, Tech(In tech I've been a full time MIS employee at a software co, a full time production worker in a wafer fab[I worked in Implant], a temp worker at a hardware co[harddrives).
One of the things I learned was that if you do not maintain your structures after you build them is that they deteriorate. Depending on how well the structure is built will determine on how long the structure(or parts thereof) will last without maintenance. Where I live, if you build a brand new house for someone, you are liable for 10 years. Your not liable if the homeowner fails to maintain the property; and, that is then determined the cause of damage was lack of maintenance.
Many home owners as well as commercial property owners fail to maintain their properties. That's because proper maintenance on properties can become expensive depending on the size, age of the structure, and who and how they built the structure. Also because some people are ignorant of maintenance through ignorance(self imposed or lied to), laziness, and unless they have a calendar of their maintenance they forget when they are supposed to do it and why.
Quality is a very undervalued asset in building unless it's a state, federal project or some residential and commercial owners who value it. Many revert to cost as the overriding concern. Cost is important, but when cost determines the quality, many times it will diminish or reduce a structures 'real' value.
Point I'm trying to get to is that maintenance requires people. Sometimes you need more than 1 individual to do said maintenance(this occurs even to professional builders). Now if your gonna be living in a world without electricity and using hand saws, chisels, etc. then that maintenance is going to take many people. Now we need people to build stuff(not everyone can do it), people to maintain stuff(most don't want to do it), and if the structure is something like a farmhouse with barns, corrals, silos then you need people to operate at efficiency for whatever you are producing/altering[back in the old days when I was a young tadpole...no, no wrong. Way back when you needed a place to smelt the ores and other additives in a separate location from where smithies were at. You would have deliveries of raw ingots to smiths who then altered the material to make items like swords, etc.].
Anyway, that's my argument for goingthe route Darkodinplus is suggesting. We need people for all those things. I just don't think we need to make it accurate as far as how many it 'really' takes to build, maintain and produce/alter products. Make a little chart, keep the math abstract and scaled down, keep it in the background and show some of the workers in stills and animations with audio and or text bubbles when creating buildings. Make it automated so we don't need to do anything with those 'people'. They would just add a little bit of interactivity, eyecandy and maybe altered gameplay mechanics to the current city editor.