Pardon me for interefering, but I think there's a problem with what people understand by "martial prowess", and how they consider "warrior culture" is related to "being successful".
Martial Prowess doesn't just mean being successful at combat. It means being famous for it. And how do you become famous for your martial prowess? By making people seeing themselves how good you are at it. Hence duels, and duel rules. Even if those rules are mere rituals that state which kind of weapon you can use, they are still important because they establish a framework so people can make comparisons between individuals/groups based on martial prowess.
In warrior cultures, the value of your opponents/enemies is worth a lot. If an enemy has a lot of value because it is perceived strong, then you will have more martial prowess - and even more if you beat them oppenly, on your own, seen by everyone.
This is where "honour" and "cheating" become a bit complex: cheating is only bad if it means you didn't really win on your own, and you're usurping someone else's martial prowess, or you didn't use your martial skills to win. What matters is what people see, and what they know. One famous example is the use of poison. If no one knows you used it, then it's fine. If they know, it can be perceived as a dishonourable tactics and still be valued because it allowed you to win, but obviously it's not as much a martial prowess. Honourable isn't defined as respect for your enemy, but as a way of fighting withing the rules that let everyone see that it's purely thanks to your martial skills that you won. For the same reason, everything that doesn't involve non-martial skills isn't considered cheating, and the line can be blurry.
So no, martial prowess doesn't really encompass "honourable fight" and "rogue tactics" equally. The result isn't really the only thing that matters - killing a dragon purely with brute force, dexterity and other "open", "fair" skills will always be valued more within a warrior culture, but it doesn't mean that "dishonourable" tactics will be frowned upon. It just means that it's less valued, because it's easier and less "martial". And this distinction can vary a lot depending on the tropes, the context etc. For example, taunting an enemy to enrage them will not be considered cheating in most cases. Poisoning your weapon will be considered cheating in some cases. And seducing the enemy so you can kill him in their sleep will only be considered a martial prowess in a very few cases. In all cases, the result will be the same: a weakness was exploited and a weapon was used to kill an enemy. But the information available to the people varied a lot - and this is what defines martial prowess. It's in the eyes of the witnesses, not in the "result".
And yes, this also mean that "Warrior Cultures" can have huge propaganda machines that tell you how succesful the army (and the elite) is. Which is exactly what real warrior cultures did/do, like the Assyrians, the ancient Egyptians etc.
In short, "Warrior culture" and "martial prowess" don't imply the same thing as "Warriors" and "being successful".