From that wiki: I know wiki is as scientific as licking paint to see if its dry but:
Heavy-weight
Large, heavy horses, weighing from 1,500 to 2,000 pounds (680 to 910 kg), the ancestors of today's draught horses, were used, particularly in Europe, from the Middle Ages onward.
Thats the horses. Now add the armour.
Thats for, as I said, the larger horses cupid. Now eat your words and rage cause you are chatting shit and cant do fuck all about it.
And now, back on topic: While it is NOT always possible to kill a cavman as he attemps to couch you, it is fairly easy to avoid his couch also, unless of course he catches you unaware, but if HE DOES catch you unaware, why do you care what killed you? Backstabbed is backstabbed, the result from both is dead.
UNLESS of course the crying is because you think that your ARMOUR should allow you to take a couch in the back and let you turn around and kill the guy, but if so: 1/ Cav have had so much taken from them, dont try to take their only nuke.
2/ Any discussions about being able to survive a couch belong in a thread about armour values.