Especially the ones that bot out of Horizon tend to be easily killed. Although you can't get the ones at the aetheryte, you can easily monster kill the bots out in the field by dragging mobs over to them and letting them get eaten by AOEs.

I had fun one day pulling every monster in the watery area between Horizon and Vesper and letting the black mage bots who were leveling there take them all off me with Fire II... Instant death. >: D

Unfortunately... they're also generally set to just come back after they die, so you can only stop them for a minute or two at best. Sadness.