Maybe I am missing something, but the study I'm looking at just looks at mass graves after a Carthaginian attack, so they could very easily have been Carthagini

Maybe I am missing something, but the study I'm looking at just looks at mass graves after a Carthaginian attack, so they could very easily have been Carthaginian mercenaries? Which would not be surprising at all; Carthage was a nautical trading state which is known to have used mercenaries extensively.