@The Fake Maven:
First of all, your original quote left out the word ממעל.
Secondly, the operative word here is חלק and the prefix מ of ממעל.
Similarly the words חלק מן האור abd the word שנתחלק (Sefer HaTal quoted above) does not infer or imply עצמות ומהות as is being suggested the Rebbe said.
Thirdly, arguably the אבות הקדושים – the מרכבה לשכינה – cannot be compared to anyone who followed them.