In the first book of the geralt saga, Blood of the Elves, the dwarws are on a haux convoy mission set by the king to test their loyality. The thing is, he lies about the fact that the dwarfs are send out because the scoia'tael would have a good releationship with them and so wouldn`t harm them. However that does make sence to me. Of cource they have a few humans with them like Geralt, Triss and Ciri but would you kill potential traitors of your enemy ? So why did they do it ?