After the Horus Heresy ended, the survivors of the Iron Hands began reviewing why the Isstvan campaign had ended in such utter defeat.
After extensive discussion and the filling in of countless details, the Iron Hands concluded that Ferrus's excessive personal authority and his momentary emotional misjudgment had ultimately ruined everything for the Legion.
They could have used carefully forged heavy weapons and dark technology to destroy every enemy surrounding them, yet in his fury over Fulgrim's betrayal, Ferrus had chosen to lead a frontal assault, abandoning the defensive plan of fortifying their positions.
Thus, the Iron Hands' upper ranks believed that the Legion should not, and would not, ever again be permanently ruled by a single individual. The Iron Council, composed of the various Iron Fathers, became the core of the Iron Hands, while the Chapter Master was merely a tool selected by the Iron Council to lead troops.
On the surface, however, the Iron Hands still fully upheld the Chapter Master's authority. After all, they had signed the Codex Astartes, the sole guide for Space Marine operations after the Horus Heresy. Although the major Codex Astartes 2.0 update had already been promoted in the Big Canteen and the Ultramar sector, the distant Iron Hands still built their Chapters according to the Codex Astartes' requirements.
It was nothing new for the original Chapters to adapt the Codex Astartes to local conditions, and the Iron Hands were no exception.
The Iron Hands did not apply the Codex word for word. The intense pragmatism permeating the Iron Hands meant that the moment the Codex arrived on Medusa, it was analyzed and refined by the Iron Fathers. They adopted the sensible parts of the Codex, retained and improved the Iron Hands' old traditions and methods, then organically combined the two into a