“Much of the abduction discussion has the same basic cast of characters (short and tall grays, mantids on rare occasions).”
The problem is that this does not cover all of the abductions—and definitely not all of the human contact cases.
Fascinating reading is the Rosales “Humanoid Encounters” series of books.
This is the first of the series:
https://www.amazon.com/Humanoid-Encounters-AD-1899-Others-amongst/dp/1542722055
Occam’s Razor is useless with this stuff—it is just too complex and there is just too much of it.
Are the encounter accounts in that book anecdotal accounts, stories that have been passed down by family, etc., OR have they been tested for reliability (multiple accounts of same occurrence, etc.)?
There have been many, many accounts throughout the years that need to be held in light regard (however much they might be true) if only because there is no way of measuring or attesting their accuracy/reliability.
The accounts described by Mack, Hopkins, and David Jacobs are the result of hypnotic regression of certain individuals who have been (as much as possible) screened for credibility. And even then they need to be taken with a huge grain of salt.
The most reliable accounts of course are those like the Ariel School account in Zimbabwe and the Westall HS account in Australia. In both of these accounts, there were multiple witnesses whose stories have stood the test of time.
In the accounts obtained via hypnotic regression, Mack, Hopkins, and Jacobs all leave open the possibility that the contact experiences might have been imagined or hallucinated (even when there was significant PTSD).