Farsi, Pashto, and Dari are all the same language family as English, but Arabic isn’t.
Yes, they are all in the Indo-European language family while Arabic isn’t. Farsi and Dari are pretty much the same language, Persian, spoken with slightly different accents. Pashtu is different from Persian, but related. All are spoken in Afghanistan, Farsi in Iran, and Dari & Pashtu in parts of Pakistan. That tells you which part of the world our military was using her for.