For the idea of making massive cities while still retaining the detail, this could, I think, be done, keeping the autonomy of the single dwarves, by making industries in quarters, rather than by buildings. For example, a corner of your fortress could be the weaponsmith's quarter, there are a number of workshops there inside one confined space. You could then select this quarter and make a work order of say, 500 axes, at priority 1. Then, when your weaponsmiths stop drinking, twenty of them will walk into the weaponsmith's quarters, each take a shop and start hammering. If you then set another order of 15 shortswords at priority 2 and another 300 spears at priority one, the 15 shortswords will be created, then the 300 spears and axes will be made concurrently (one axe then one spear, for example). These quarters could act as groups do in RTS games, you select them, put them into a group, and then you can select them together to do a task. You could also seperate them, say if you wanted a legendary weaponsmith to make axes and the rest of them make hammers.
If it was done like this, it'd strike, I believe, a nice balance between detail and ease of use. If population cap was an easily changed value, say on a regular menu, then it'd be easy to just say, ok people with gaming rigs, go wild. You people on dinosaurs, well, go wild, but only with 40 dwarves.