Orks;
Da Boss says what they do, because he's da boss and I believe he'll, uh, Krump was it? He'll Krump any grott that says otherwise.
Which is to say, yes and no?

As long as the SC agent is able to project enough general Orkyness he should be able to get the Orks to co-operate. If he ever falls beneath a certain level of percieved Orkyness, the whole lot will turn on him and his guys, regardless of how many they kill. (If they kill enough at this point, the remaining Orks would simply flee, so they can come back and have another go later).

Nobs, as far as I know, already act as a basic sort of police force. A very basic, very brutal yet cunning sort of police-force. As long as fighting each other isn't something that you try to regulate and most crimes are punished in an Orky enough way, it might hang together. The bonus is that you don't necessarily have to explain any of it, because you is da boss. The downside is, Orks know what is and what isn't Orky and that's a line you'll have to try very hard not to cross.

It kind of depends on what the Agent expects to be able to do. If your goal is to "Reform" the Orks, without genociding them and starting from scratch, then you'll have to be careful not to aim too high. If you can keep your expectations low, you may just acheive something.

For example, Orks are for Fightin and Winnin. You can't have nonviolent Orks. You just can't have them. It's built in at a fundamental level. You could, though, perhaps steer the Orks to a point where they target a certain foe almost exclusively, or get them to the point where they will trade with other races and so on "peacefully" when they aren't actively waaaghing and/or off for a good fight. You might be able to get them to refocus some of their urges into metaphorical fightin' and winnin, steering their society from simple bloodshed as their method of resolving their internal differences towards bloody sports instead, but the net effect of that would just be more Orks.
What does the Agent hope to acheive?