Boundaries like that don’t work, because, depending on the region, 5mio. could easily be your mom n pop shop or local doctor. Maybe we could tie it to certain tax indicators?

Either a black stork, a least weasel (actually pretty common, but difficult auf to see around here), Cerambyx cerdo (probably not as rare as most regulating bodies think), a Eurasian eagle owl (rare around Germany) or felis silvestris

So they have councils that influence politics. Within a republic. A Soviet republic!/s