It's late, I'm kinda tired, and the tag at the back of my neck itches. That sounds like a perfect set of reasons to talk about fighting dirty through history. There's a lot of groin popping in literature, if you know what to look for.
My first example comes from the collected romances of Chrétien de Troyes from around the 13th century. You have to realize that the world was absurdly different back then. Men wept on eachothers' shoulders when they parted, war was the accepted, constanst, state of affairs, they didn't have the Late Show.
An Arthurian Romance (so called because they usually involve the big man or one of his knights) usually had three elements; the knight's horse, his sword, and his woman. He would start with some combination of these three, and have to strive to acquire the third. Sometimes he'd lose one or more of the three and have to reacquire them. I don't know if it's significant that two of the three relate directly to fighting and only one to sex.
Anyway, one of these stories begins with a young knight out hunting (on his horse). As I recall, he's hunting a stag. Unfortunately, calamity strikes and he receives a wound to his thigh. I'll let you know right now that that's a euphemism for groin. We know this because his mysterious leg wound in no way hampers his ability to fight later in the story, and because the only way his wound can be cured is by the touch of a woman. Appropriate, because this young man was notoriously unmarried.
Anyway, he gets in a magic boat and rescues a woman trapped in a tower married to an old man who, we are again euphemistically told, needs Viagra. Some things change, some things don't. By the way, most Arthurian romances involve dashing young men stealing the wives of older men. Gawain & Lancelot, for example. Lancelot's story [The Knight of the Cart] almost got Chrétien punished by the church for showing Gwinevere as an adultress. At least Gawain, the perfect knight, had the decency to kill the poor bastard first.
Actually, this is an interesting reflection of a situation that persisted for most of our history. Women had an unfortunate tendency to die young, often in childbirth. Men had a tendency to not be worth marrying until they were older and had accumulated some real estate and wealth. So most brides were taken up by older men, which left the landscape awash with unmarried young men, many of whom spent their entire lives preparing for war. This was an age of conflict, remember.
So you get a bunch of horny young men with weapons and nothing to do... The result should be easily predictable. "What dost thou rebel against, young master?" "What hast thou got?"
Why do you think Norman knights conquered Sicily? They had nothing better to do. And they couldn't get away with that sort of back home in Western France. Why do you think people were so eager to send knights off to Jerusalem? Because they were wreaking havoc on the countryside at home; better they do that sort of thing to the heathens.
Anyway, back to thigh wounds. They show up all over the place, because everyone was imitating the best selling book of all time. The first recorded instance of anyone getting a shot to the meat and two veg occurs in the Bible. Jacob wrestles with an angel, who "knocks his thigh out of joint". "The mighty sinew there shriveled." Jacob doesn't have any more kids after that fight, and most Biblical figures are fecund out the wazoo. That angel fought dirty.
Let's face it, there's really nothing new we can bring to the table concerning fighting. They knew how to knock each other about back in the day.
I'm sure my Uncle Ben can correct me all over the place on this post.