Such knights are not so much brave as very very dumb. Or else, they don't particularly care for their kneecaps.

Cimorene thinks about it, "Well, if the prince is important enough he has his own personal herald to do the job. The less important ones just have their squires do it. But I don't think they normally bring heralds to dragon-slayings. After all, the herald would just get eaten, and good heralds are so hard to find these days."