And perhaps that is just a ruse to invite an attack on that flank. It's a common mistake to believe that the shield wall is a purely static defensive tactic. It is not. It's fluid and adaptable to the situation. Example: https://www.youtube.com/watch?v=AiKIJXXSjNk The Koreans clearly said to themselves, "Why reinvent the wheel when it's already been done?" What you are seeing is a modern application of Roman century level tactics. Every formation and movement is straight out of the Roman legions play-book. Steal only from the best.