What the senior practitioner is bringing to that dictation is their experience and knowledge about how such documents are to be structured, more so than their experience at dictating.
Because the senior practitioner has the experience to know how to set out the details of a pleading, the order in which the pleading ought to be organised, the necessary factors that must be included in the pleading, and enough knowledge of the relevant file that they can dictate without constant pauses, it appears to the untrained eye that the practitioner is simply doing the dictation unprepared.
The reality is that as a young practitioner lawyers ought to plan more complex documents in advance of dictating them. It is tempting to simply type longer more complex documents yourself, however, that is missing an opportunity to improve your habits, your abilities, your efficiency and productivity when it comes to the production of longer documents. Rather than give up in advance when faced with a more complex document, what you should do is to plan the document.
Source: Tips for Lawyers