I read the englisch version and too some extend that is plossible.

What the base for rotation troops, is essentialy a battle pulse that occurse becouse of fear, if u r able too confront the first charge u'll get a battle pullse that will allow u too rotate troops, still its very very risky in my opinion and nothing like depicted in the movie.

Later it talks abut deeper ranks not giving any advantage and its so so. The principle for deper ranks is only when full army is commited into the push, and yes this type is very easy too disrupt if flanked or completly stoped, thats why romans stoped using it too a ceartian extend. Deeper ranks only help u if u have a steady push with good flak support, nothing new.