Although today many TCM herbs are from monocrop plantations, traditionally, they were gathered from the wild. Some grow best in sunny open areas, but many were harvested from the forest. There is no reason why a
permaculture site cannot offer all the niches needed - some areas of deep shade, some areas of dappled light, some edges, and some open spaces.
I personally would like to see more Eucommia ulmoides
trees grown here in the US - the bark is very useful for the kidneys, blood pressure, arthritis, lumbago, cholesterol, etc. I would be growing it, but it is probably too warm here, that tree requires more cold.
Peony is a lovely plant, when I was growing up in Illinois, my neighbor had them growing under the shade of some oak trees. That
root is valuable for many conditions.
The Angelicas (including dong quai) are lovely plants for more open areas. Lots of different uses for those in Chinese and western herbalism.