The point about the Garamantes is that they were not exactly anyone’s “neighbours” in the sense that there was there was widespread cultural exchange, intermingling of populations, or even a profound existential threat to another power in the same geographical area. Their incursions into Roman/Mediterranean power-politics were as half-hearted allies of some much more problematic characters, such as Juba, who did frighten the Romans (briefly). They didn’t make much impression on the Persians or Greeks, who were actually far more interested in “Who exactly was out there” than the Romans were and could be counted on to tell the tale if there was one, or at least make it up. That’s what is fascinating about the Garamantes. A whole civilisation dependent on a particular eco-system, which would be destroyed when it failed and leave not much trace. Note to all of us.