"Excessive"? In a story about knights? Not... really. Not if you're trying for realism.
Oh, we romanticize knights these days, but our depiction of the middle ages is not even close to historically accurate and I'm not referring to magic or dragons. Hell, that part was...sort of true. (It's kind of sad how little the general public knows when so many people are fond of using that time period in stories.)
Knights were kind of assholes if you weren't of noble blood. Yes, "protect the innocent" was a rule, but it applied to women and children of the upper class. >_> Peasants? Not so much. Even the church encouraged brothels to keep knights from raping lower class women on the streets. (Funnily enough, peasant life was better than we think.)
However, going the fantasy route... sure, knights are the paragons of goodness and justice.