III-4 is, on the other hand, relatively barren, with rather large rifts and only 23 systems, most of which are clustered in the southern two thirds of the subsector. The edge of the Cartel just barely hangs over the subsector line, but this is mostly an Imperial sector.
A hodge-podge of different colonies and a few allies and independents—and then on a whim, based just on the geography of how this settled out, I created the Reaver Worlds; a large, powerful federation (that I literally hadn't thought of until right now). If you think of the Comancheria in about 1850 or so and put it into space, this is what it would look like. It's a long, thin polity; this is the western half of it. The eastern half is nearly as large in the last subsector. I count 28 worlds here; an average density subsector, more or less.
Finally, IV-4—the last subsector. Unless I miscounted, I got 35 worlds; I think my densest subsector. Containing the rest of the Reaver Worlds, the rest of the Empire's frontier, and a few other scatterings of other things here and there (including rather precocious colonies by the Berns and Republic, otherwise far from their main areas of strength), we're done!
I get 118 worlds in this domain, which brings the sector total to 421. In the last domains, I thought I was running a little light, but the law of averages caught up to me, and some more heavily populated sectors here at the end bring me up to within about half a dozen of where I predicted I'd be mathematically. That means... 414 systems to generate! The real work; but it's fun work (if it doesn't start getting tedious, that is.)
I won't post the full sector map yet—let me, now that it's filled in, draw out some space-lanes and label some of the polities that are big enough to merit a full label