Phenom here... There was a case in Germania a while back about duplicating a city which changed considerably from one period to the next. Squashing that rubbed me the wrong way. The goal should not be to create a nice tidy group of hoods that perfectly reresent a specific period or timeline. The goal should be to create hoods in which people want to contribute content. Otherwise, we get a perfect little package no one wants to open.

I disagree with the quota concept. Quotas don't work in real life they won't work here either. If one person wants to create content for a hood, create the hood.