Do you have any examples of when this actually happened (a fight "continued, to protect the nobles, once the enemy got through the walls")? What I find most interesting is applying Occam's razor, it's almost certainly not a defense mechanism, yet we have dozens of HN folks defending it, and I'm not sure why? If there was at least one documented account of where this was an effective defense, then maybe there's something there.
In 1201, Eleanor of Aquitaine survived in the keep of the castle Mirebeau after attackers were within the walls, until her son King John arrived and captured the attackers, rescuing her.
Because it is a truth most of us have accepted without question. Further, it is so agreeable to other facts. Left handed people are evil? But of course, they can attack up in castle staircases! Medeival life was one of constant sword-fighting and war time!
Also I'll admit the first couple arguments in TFA felt weak. I wouldn't be surprised if that colored peoples readings of the rest, or if they jumped to come comment before finishing the rest.
