Are they largely unchanged now?
My understanding is they derived from principles JFC Fuller wrote after WWI. There was widespread horror about what had happened and consensus that military thinking and tactics needed to change. The Principle of Maneuver is a direct repudiation of the frontal assault tactics that caused so much carnage in WWI. Fire and maneuver became the basic small unit tactic of the US Army. It was classically executed in the attack on Brecourt Manor by Easy Company, depicted in the Band of Brothers miniseries.