Pursuing Simon's comment, I wonder if there is any evidence that scribal workshops would ever produce many copies of a work at one time, with a single reader and a number of scribes. I believe this is attested in the Roman world, but can't give any citations. Presumably there would be a market for standard classics (e.g. the Gita) that in some circumstances would justify producing them in advance of specific individual orders. It is also possible that new works might gain a reputation generating a demand for many copies quickly, or that a patron might pay for many copies for free distribution. But everything I recall reading seems to assume that copies were produced singly. It need not even be a question of one person recruiting scribes so to speak off the street; it could also be a
workshop of a scribe and his sons (younger brothers, nephews, etc.), a family operation.