We don’t have access to the documents in question to clarify if it’s truly what it was stated or the author’s unfamiliarity with the subject (and perhaps even the language barrier) made him write something not fully accurate.

The DeCavs have been described as a low-tier group in the northeast for quite a while. So it does strike me as odd to see them being referred to as “strong”.

As for the estimates for each family, I do think those numbers are believable.