Given that they found these in Bavaria, it's probably moot, as that's squarely in the area you would expect to find lactose-tolerating people, but everything I've read says that goat's milk has lower lactose levels than cow's milk. And, weak evidence, I know, but just about every piece of fiction I've read that featured babies that needed to be kept alive in the absence of their mother or a wet nurse has gone to goat's milk first - off the top of my head, this features in Ken Follet's Pillars of the Earth.