OoH was founded in 767. So 455 years.
Fine with 1000 magi average.
Fine with .75 spells/year, and sure, 90% are vanilla.
I don't see why a mystery cult would necessarily value texts more highly; some would (the truth is in the texts) and others not (the text is but a stepping stone on your personal path; now you must Sacrifice it for your next initiation!) I also don't see why normal hermetic texts would become obsolete more than cultic spell texts, especially for Theurgy spells that no longer have spell spirits. If you say 75% for HT, I'll think it's at least 75% for the rest of the Order.
Not all cults have great organization or sense of purpose. Merinita and Titanoi vs Tremere and Guernicus? I'll go with the latter for organization and sense of purpose. 10% duplicates vs 60% duplicates? Really? Even when any Theurge who wants to be sure his Theurgic Pilum of Fire is available when he needs it absolutely has to invent it, so you end up with 5 different versions of the same spell?
Between your values of 30% retention and 40% originality (12%) for the Order vs 75% retention and 90% originality (67%) for the Theurges or any typical cult with weird spells, you've made cultists more than 5x more efficient than other magi. Yowsas. Even though it could just as well go the opposite way. Perhaps an especially efficient cult might enjoy these values, but as the norm?
Ok....
But if we assume that theurgists are pretty normal, then using your idea of normality, those 455 spells become 80-90 spells for the entire cult, and they are willing to share those spells at around the same rate as other magi, though perhaps for different reasons or in exchange for different consideration. And now we have numbers that look reasonable to me: ~25K vanilla spells for the Order and ~85 special spells for the typical cult that has such things...
But MMVs.
Anyway,
Ken
Edit: ~25K spells --> ~33K spells, due to age of Order
I was thinking that their history is longer, a greater proportion of 300 year old spells will be obsolete than 100 year old spells.
Yes MMV,
I was positing a cult that really cared about retaining their theurgy knowledge. I think that this makes sense in that they know that there are only a few cultists and they don't have the rest of the order to fall back on. One could also imagine a cult where secrecy is paramount and they share very little. I was looking for a situation where characters with hermetic theurgy get more value from their investment.
That's fair. We can also consider entire sagas in this vein: How communicative is your Order of Hermes? Does your House Bonisagus really promote the knowledge of magic (as is suggested by the core rules) or does it only pretend to (as is suggested by the house writeup in TL)?
I was seeing things through the lens of most sagas I've seen: Even 'core' spell texts are not all that plentiful or freely accessible, and everything you get from a cult requires a favor or exchange skewed to the benefit of the master.
This is a thing. The OoH seems much more ... is "helpful" the word I'm looking for? "Non-competitive" perhaps? ... than in any of the earlier editions. The more aggresively competitive the OoH is internally, the more restricted access to labtexts will be. Or perhaps that is exactly the benefit of being part of a mystery cult? having sodales you can trust - and who're willing to share their secrets with you.