This is great, Larry, thx for your clarifying response!
Also really fine of you to give away that "the root source material is cryptic and translated many times, so I rely on English interpretations., therefore, my understanding will not be complete. "
Here, I would like to offer you some suggestions and additions which might be useful for your further study:
In Buddhist Studies, I'd say that everything post-Nagarjuna is considered "late" - and this means, in most cases, that the transition from Magadhi and other vernaculars to Sanskrit was completed by the time the philosophers were teaching (and writing, if they did). For this reason, most Mahayana texts have originals in Sanskrit (or did so before they got lost).
Admittedly, Nagarjuna (appr 150-250 CE) himself, was (most probably) not an adherent of Mahayana as such - for his exclusive use of the (Pali) Tipitaka in Mulamadhyamakakarika seems to point at his urge to make a case (if any) for the Stahaviravadin view. Yet, his language was Sanskrit.
Chandrakirti (7th Century CE), surely the most famous commentator of Nagarjuna and Aryadeva's work, in fact was the one laying the groundwork for Tibetan Buddhism. Sadly, very little of Sanskrit originals have survived, so we have to rely on Tibetan versions - and, perhaps, use the lectures of the 14th Dalai Lama as a study guide (see a/o The World of Tibetan Buddhism (1995) - a compendium that I have translated into Dutch and published as "De Wereld van het Tibetaanse Boeddhisme", Den Haag 1996.
Shantideva, the author of Bodhicaryavatara, followed suit in the 8th Century CE. By that time even Sanskrit had become seriously eroded - yet still fashionable enough for clear understanding :-)
In this paper, you can find a list of the available manuscripts: https://www.duo.uio.no/bitstream/handle/10852/24076/Liland_2009.pdf?sequence=1
As a final note, I volunteer to admit that I seriously doubt that any of the above philosophers would have used the word "mystic" to describe themselves. Rather, they were logicians - and, certainly in the case of Nagarjuna, ventured in the field of applied mathematics to look for more questions and postulate possible answers (if any).
Perhaps, even the historical Buddha was not a mystic, but more of a pragmatic thinker.
And oh yes. Apart from the historical Buddha himself, surely, none of the above were alive 2,500 years ago. If Nagarjuna is nearing 2,000 - Shantideva is 1,500 at the very most. :-)
Love talking to you, Larry. Perhaps we should look for another channel to do so?
