I just had a thought about how one could manage high density population : if a city is expanded to host more NPCs, it could still feel empty because of the ( NPC number ) / (city area) ratio. And it would even more confuse the player due to large, low-density sections. What should be possible is to replace actual city buildings by ones designed to host a LOT of people. Most of the Skyrim architecture is composed of personnal, two- or three-stored houses (including the basement). I only played TES IV and V, so I don't know if the previous games featured apartment buildings, but in any case I think they are the solution. Furthermore, I think that some architectural styles can really benefit from vertical building (over-ground for areas like the Imperial City, and underground towers for Dwemer cities like Markarth ). If that was the case, each building ( let's say 4 apartments per floor, 5 floors per building, one lounge (or whatever), and a central staircase ) could host 20 families, meaning 30 - 50 NPCs per building ! That way, any high-density area could get its 300 citizens for a very moderate space. :biggrin:
