For an actual attack on a town, say, one they have no real relationship when they are just passing through, it is usually a more "Grab the boys and the young women!" situation more than "Lay waste to everything" because they don't really need the land of a town, nor "grab the tools and resources!" because generally they only carry the tools and resources they need at the moment, with a little extra for replacement; only really burdened when heading for a town to trade. They see no need to stockpile tools and stuff since they have already relationships with towns closer to their prowlands who are happy to trade wheat for hoes.
Boys are desired for membership, women are desired to sell as slaves to other Nursuries.