I've always had a soft spot for Captain Tilney, perhaps owing to his wonderful brother, but here is how I've always read this situation.

Captain Tilney, as the eldest has no doubt had his share of marriagable young women thrown at him, whether of their own or their mother's doing. He would have been exposed to all kinds of people (not just women either). What Henry is saying to Catherine here is that Frederick treats people with the respect they deserve.

I think this is normal and healthy. It is after all, what we all want of Catherine, is it not? To recognize what John and Issabella Thorpe really are and to stay away from them?

Frederick sees what Isabella is about almost immediately (he knows she is engaged and yet she is most obviously flirting with and trying to snare him). Instead of just ignoring her, he teaches her a lesson in her own medicine. The stuff of heros? Perhaps not, but it is a bit of a "yess" moment when you see Isabella get what's coming to her.

We don't see enough of the Captain to form our own opinions of our he treats others so we rely on Henry and Eleanor to tell us about him. They seem to like their brother and I must believe them. The outcome is exactly what was wanted - James is safe from Isabella and Frederick is safe from Isabella.