> If there is even a slight or possible advantage to one direction then it would make sense to build it that way
If it's true that the battle at this point is lost for the defenders -- and known history indicates this is so -- then why would the builders choose directions based on this extremely unlikely scenario, instead of on just about any other consideration (aesthetic, practical, or even random)?
I'll take a stab at guessing (mind you, this is blind guessing, happy to be corrected!): the USMC still issue bayonets because of both tradition, which is important to the military, and also because they are actually useful in close quarters battle, which still occurs on occasion, such as in urban warfare and house-to-house combat clearing, etc. The likelihood of having to use a bayonet/knife in modern CQB is probably significantly higher than the likelihood of medieval defenders recovering from an enemy army that has stormed their castle.
If it's true that the battle at this point is lost for the defenders -- and known history indicates this is so -- then why would the builders choose directions based on this extremely unlikely scenario, instead of on just about any other consideration (aesthetic, practical, or even random)?