I guess I'd be inclined to translate ἀγαθοί in those contexts as "decent" or "respectable." Reminds me of Cato's definition of an ideal orator: vir bonus dicendi peritus, "a good man skilled at speaking." Δημαγωγοὶ ἀγαθοί might = "respectable politicians." In my experience with ancient Greek, a person is called ἀγαθός when he does or says the right thing at the right time.