So, I finished up the arable regions and their populace. I had started with a figure of 19,530 total inhabitants for the barony. After all the arable regions inhabitants were subtracted, I had 17,208 people remaining.
The guidelines suggest taking the square root of the population (which is 131) and multiplying it by a randomly generated number (2d4+10), where I rolled 3 for a total of 13. The largest non-arable producing center in the barony would then be a Small Town of 1,705 inhabitants. My sensibilities thought this was fine, but when I started reducing 1,705 by a random percentage (2d4x5%), I got two more towns of 1,279 and 1086 persons, and a village of 760. This left me with a staggering 12,378 people in a multitude of tiny (<760 inhabitants) villages, which is not ideal for what I had envisioned!
Think I will call it a night and mull this over. My knee-jerk reaction is to start with a Large Town, or even a Small City, and then reduce it to eat up some of the population...
"OH NO! GODZILLA!" ~ resident of my starting barony