I believe he is with Elite now.
Ok. My thoughts...
There wasn't a lot of content, but he mentions some terms that are commonly used in discussions of hitting mechanics on DFP and other similar forums. If Pierce's instruction aligns with Stone's, then I would expect some useful information along the way.
I agree. I have seen some other "Pierce" stuff. It aligns fairly well with Stone and has overlap with Tewks and others. As with most of this stuff, there are typically some grammatical differences.
In this segment below he discusses his views .... swing not in the frontal plane .... swing in the sagittal plane .... external shoulder rotation .... rear leg pivot.