How we cite our quotes: (Book.Chapter.Bekker #s); all Bekker line numbers are approximate, since they are keyed to the original Greek.
Quote #1
But experience of particular things seems to be courage as well. So it is that Socrates too supposed courage to be knowledge. Yet different people are experienced in different things, and in matters of war, it is the professional soldiers who are such. For there seem to be many false alarms in war, which professional soldiers especially see through. (3.8.1116b4-7)
Aristotle has a lot of positive things to say about "knowers," or people who seem to have a head for knowing something, as an expert might. In this case, having professional knowledge (an intellectual virtue) can lead to displaying a moral virtue (courage, in this case). However, knowledge only gets you so far. For these "courageous" soldiers, things begin to fall apart when they enter into unknown territory, whenever something exceeds their experience.
Quote #2
But the magnificent person resembles a knower, since he is able to contemplate what is fitting and to spend great amounts in a suitable way. (4.2.1122a35-36)
We're getting at knowledge once again through a moral virtue. A magnificent person (one who expends large sums of money for the greater good) can't just throw his money around. He has to use his intellect (and tact) to understand where it'll best be used and how the work to be done with it will be made awesome. This requires both thought and sensitivity, something that comes from understanding the needs of the community.
Quote #3
Similarly too, people suppose that to know the just and unjust things is in no way to be wise, because it is not difficult to comprehend what the laws say (but these are not the just things, except incidentally). But how the just things are done and how they are distributed—this is indeed a greater task than to know what is conducive to health... (5.9.1137a10-4)
Though both wisdom and comprehension are both intellectual virtues, Aristotle's pretty clear here about which one is superior. Simply grasping intellectually what lawgivers say about justice isn't enough to maintain the balance of society. True wisdom in this case requires both perception and experience to understand how justice works best on a day-to-day (and case-to-case) basis. It's not hard to imagine that Aristotle's responding to those who maybe poke fun at the "political art."