Direct answer
Objectives follow journal display order. Some depend on your choices; follow the active objective in the game.
Result
Discipline is the backbone of any army. Everything must be written down, every order signed and archived in triplicate. This proved a boon to Geralt on one occasion, when he came across a document written in a soldier's hand. It was sparse and contained few details, but what it did divulge was intriguing, to say the least...