Like the brother said, basically that those two are "slaves of the British/Americans" that they've captured. "Da Angrayzan ghulaman," meaning slaves of the British and Americans. They are using "Angrayz" to refer to English speakers, I believe, not just the British. It doesn't sound like he says Mullah Dadullah. Yes, an Afghan would understand. The differences are mainly in accent. The grammar and vocabulary are the same. Some speakers will use more Farsi words. The Qandahari dialect is the standard dialect.