He uses both “good man” and “good citizen” as terms of art. “Good citizen,” which he describes in some length in the Politics, basically is someone who can further the goals of the society to which he belongs. A stalwart SS officer would have been a “good citizen” of Nazi Germany. Socrates, Christ, Thomas More, and other martyrs were not “good citizens” of their respective societies.

Aristotle does not define “good man” in his Politics. However, it is generally understood that the qualities he sets forth in his Nichomachean Ethics define what he means by the “good man.” This broadly resembles the “truthteller” you are referring to – although obviously in his book length discussion; he discusses many other qualities as well. The proud, arrogant, domineering Coriolanus, I am sorry to say, falls short of many of Aristotle’s criteria for the “good man.”

In any event, Aristotle also wrote the Rhetoric, the art of persuasion, the purpose of which was to enable people to speak the truth in a manner that others would find to be persuasive – thereby enabling society to move from some relatively bad state to one somewhat better.