My thoughts on Yunnan and green.
1. A labor cost in Yunnan is much cheaper than long-time green producing provinces like Zhejiang, Jiangsu and Anhui. Furthermore, there are numerous tea trees grown in Yunnan...many are not drinkable tree species and not being cultivated. But Yunnan is still the only province where some unreported oldest trees can be found place to place
2. Tea trees are different. Tea tree in China (except Yunnan), Korea and Japan is the small-leaf-variety (same as Darjeeling). Which wins in subtlety and is praised when grown on high altitude. And it's been a notion for years in China, that's why those tributary teas in Yunnan during Qing dynasty were small-leaf-varieties from the six famous mountains.
When tea trade with West flourished in old era and decided to export leaves from India and Sri Lanka. Many worried because tea trees there were different from the Chinese ones. The worries shortly disappeared, they found out the big-leaf-variety (and cultivated) tastes better with oxidation. That's how India and Sri Lanka's black teas got its fame. The same knowledge can be applied to Puerh and its fermentation.
Before 50s, no one took a consideration to Yunnan and its major big-leaf-varieties. So HKers when they purchased Yunnan leaves in cheap price, they just left in garage being neglected. The weather in HK is very wet, when HKers tasted Yunnanese leaves after decades..the taste came much better with a camphor aroma, that's how Puerh legend began.
the small-leaf-variety and the middle-leaf-variety are still grown in Yunnan...and very young buds from the big-leaf-variety are very drinkable..(I don't know Yunnan greens are basically which one)..I talked too long...just choose what you like...that's what I wanted to say