An honor-bound orc? I'd say they'd definitely be adverse to stalking the shadows and killing enemies before they had a chance to defend themselves. If you've ever read http://www.imperial-library.info/content/oblivion-how-orsinium-passed-orcs, you'll know what I'm talking about.
Someone said earlier in this thread that Orsimer are like lions.
I would honestly compare it more to wolves, which have a somewhat similar structure (although the chief not doing much is more akin to the lions), but basically, imagine the sort of honor that pack-hunters like lions or wolves have, and you have the "honor" of the Orsimer.
It is not the honor of formalized rules that are created to give the knightly classes the "fair fight" they know they have an indisputable advantage in due to better equipment and training, but rather, the "honor" of knowing that the legitimacy of their accomplishments rests upon the strength and worthiness of their opponents, and that there will always be a greater foe to face the next day. To slack, to take the easy way out through cheating or belittling their foes through unnecessary deceit is to give themselves a lesser challenge to strive against. Play a sport or a game like chess, and you'll see that the fastest way to become a better player is to play against someone better than you, even knowing you're going to get your clock cleaned. Strength comes from defeating strong foes, weakening your foes will only make yourself soft in the long run, and softness leads to death.
With that said, no lion and no wolf just blunders headlong into their prey. Pack hunters always use subterfuge - they have to, their prey is often faster and larger than they are. They'd hunt alone if they could just kill their prey toe-to-toe. Wolves and lions are ambush predators, and to be unaware of your surroundings is just another form of softness to be exploited.
Of course, this isn't alien to all forms of honorable martial codes, as well. The Samurai carried their blades with them at all times specifically because they were always considered valid military targets for assassination or duels. There is even a school of martial arts that specifically trains for how to respond to assassins jumping out at you from every angle of attack and from every starting position (such as being in bed or kneeling in prayer if you are attacked at your local shrine) just because being ambushed was a fact of life. Oddly, this school of martial arts is still taught to businessmen, of all things, as it is supposed to be a way of training yourself to always focus upon the minor details and always be alert, even during your down time.
The Orsimer are ruled by the coldest and harshest laws of nature, so essentially, "might makes right" may not necessarily be true, but not being mighty makes you dead, and then nobody's going to care how right you may or may not have been.