Repetition of articles in a sentence
He is a better counsellor than a scholar.
He is a better poet than a novelist.
Both of these are ambiguous. They could mean he's a better counsellor (poet) than a scholar (novelist) is or that he's better at being a counsellor (poet) than at being at scholar (novelist).
The other two mean that he's better at doing the first than at doing the second.