Human Slaves in Chaotic Domains

From Domains of Chaos in Axioms 2:

Beastmen are poor farmers and herders, even when taught civilized methods. Once the population of a chaotic domain exceeds 125 peasant families per 6-mile hex, the excess peasant families will provide only 1⁄2 the normal land revenue.

Does this limitation apply to peasant families composed of human or demi-human slave laborers?

NAA, as per usual, but I'd bet beastmen are poor slaveowners (in the vastly relative sense...) as well and don't get from them as much as they ought.

I considered the possibility that beastmen might suck at everything, including slave owning. On the other hand, intimidating weaker people into doing things for them might be an area where beastmen excel.