Ah.. realism you say? Elliott was not nearly as attractive (=less of a danger, even in the mind of the author, I venture-- its not a coincidence he is related to Anne! )
Otoh HC was (apparently) as reformable as a boy can get without actually being good = seductive
(Should have made clear that it's from Wellington, an admirer of Napoleon https://www.quora.com/What-is-the-meaning-of-Wellingtons-quo...)
Update: Austen could have gone with cool vs bad[0] but that wouldn't be drama would it (& she's been there: that business with Mr Darcy, quite cringe to modern readers no?)
[0]https://news.ycombinator.com/item?id=44423529