It was Li Enjiu's student who beat one of the top PRC sanda fighters, not Li Enjiu.
Here are Li and several other of your "famous name" Chinese taiji teachers testing each other back in 1992:
Can you point out any moments of "really top level taiji skills" in this gathering of PRC masters?
Here is the son of another famous name entwined with a "grappler" of unknown experience:
Can you point out any moments of "really top level taiji skills" in this video? You certainly can borrow ideas from others--this clip has been discussed a lot online. I'd be interested in your observations based on your taiji experience.
Your statement about taiji in the United States is telling in its sweeping ignorance. You clearly don't have much experience with top-level taiji people in the US. That would be like me saying that Canada doesn't have a single person who really has top level taiji skills, and ignoring Chen Zhonghua or your teacher Yang Hai.
That a North American teacher is not heard of in the PRC does not equate with them not having top-level taiji skills. Most of the very good PRC taiji practitioners I met have not been heard of in North America. So?
Finally, the "big names in taiji" like Chen Xiaowang, Wang Haijun, et al. spend as much or more time outside of China, including the US, as they do in China. For CXW and his seniors like Feng Zhiqiang, in fact, it was the high level of interest (and dollars) from foreigners that probably saved any semblance of martial taiji in the PRC. The government recognized a good potential source of revenue when it saw that interest. And that interest showed in the lament of many top Chinese teachers at not being able to find Chinese students that showed the same dedication to taiji training that many of their better foreign (including North American) students did.
I'd suggest you get around in the US and put in as much time and effort as you did in Shanghai and other places. It might open your eyes a bit.