My God, I've really crossed the moral event horizon here, haven't I?
An XML dump showed that there are about 500 humans in the world. Still about double the number of dwarves, and roughly on par with the elves. Goblins outnumber everyone else combined. But anyway, these 500 humans were spread out in 5 hamlets surrounding a single market town. These hamlets were my first targets. The first, Angellances, had only 20 residents. The next, Coldhammers, had nearly 80. The third was Waterhearth, with 50 residents. Fourth is Shellabbey, with about 60. The fifth, called Peakslipped, is 90 strong. The rest live in the market town.
I gathered a group of dwarven soldiers, and set off to do our work. Angellances and Waterhearth were first, and I managed to destroy both villages in a single day. The next morning, we attacked Coldhammers. I logged in the middle of the fighting there. The peasants are actually really tough, and are able to use their various knives to deadly effect. The preponderance of woodcutters is slowing our advance as well. I've lost 7 of my 12 followers already (albeit they were the worst armored of the bunch.)
Anyway, all told we're about a quarter of the way there. I expect serious resistance when we reach the market town, but until then I don't expect any problems. If we keep up our momentum, the hamlets will be cleared in 3 days. The entire campaign will probably take 4 or 5. From then I can hunt down any stragglers, and the three or four army groups that are out and about. I imagine they'll return when their homes are threatened.