From my understanding (as limited as it is) Hun Yun Zhuang is a modernist interpretation of zhuagfa brought into modern parlance from an obscure past shrouded in secrecy.
As I recall from what I thought I understood from some of my teachers of the past
1. Zhuangfa's pre1700s practice was present in the xinyi/xingyi matrix of learning i.e. santishi which was synthesized from previous learning methodology
2. Shaolin had/has a mabu training stance (excessive in conditioning per damage of patella complex) while saying the adaption for yangsheng purposes allowed for adapted height and heath considerations
3. Zhi Guan methods speak of a quietness /meditation posture(s) encompassing lying down, "sitting in oblivion" posture and standing
Some of this is documented in some of the works by Livia Kohn so check out some of her works for reference. Very academic and sighted throughout her bobliographic.
In my short lessons with Chang Dungsheng, he was not into zhuangfa (at least public acknowledgement of it and he was a hsingyi/xingyi practitioner taijiquan and primary art shuaijiao), If I recall correctly he did state (through translation) that he was not a fan. Prof Hou Chi Kwang rarely mentioned it and not part of training. Lu Hunping xingyi's did not mention any relationship with zhuangfa hence my use of it (zhaugnfa) being a "modernist" bent with obscure staking added to present teaching methodology. Still positive..
Only restating my view. Since I have taught at a local acupuncture school, I try to bring up present people like Livia Kohn who actually gives a historical bent to a reality often obscured by ignorance, innuendo and downright false points of view. It also helps that students can go back to these sources and see for themselves the background of CMA in a real world matrix
Livia Kohn Introduction
http://www.bu.edu/religion/people/faculty/bios/kohn/When fascism comes to US America, It will be wrapped in the US flag and waving a cross. An astute patriot
I'm having an easier time of it, this time.
