Is it feasible or worthwhile to discuss the personality traits of fictional literacy characters?

I am an English teacher but sometimes wonder if I’m spouting complete drivel. How can I tell a class of students that Macbeth was a troubled soul, driven by his greedy wife and his insatiable ambition when in reality he’s largely a product of Shakespeare’s imagination (I know there WAS a Macbeth) I’ve never met the guy and can’t possibly claim to know anything about him.