Specialists and advancement

Do you play scribe specialists this way? Or are they always churning out books 4 seasons a year, or at least more than 2 seasons a year? I would imagine that most PC covenants, and even NPC covenants aren't thinking they can only get 2 books per year from their scribe(s). If they are, I'm a bit suprised.
Note, nothing in what I said is about working more days or extra hours. The amount of production is based on a Magus working a standard day, 10 hours, and has the sabbath off (or a rest day, if you prefer). The 10 hours, in the medieval paradigm is probably not all that long a work day. The serf in the field or pasture is probably going 12 hours or more a day. And knowing how farmers are, they are working all day, every day, despite holidays, so the scribe DOES have it easy.