How would you define this list of breakaways from Judaism?

Question

I don’t know so much about history and theology, but I saw the following list and I was hoping that someone could help me understand it;

I saw R Dovid Gottlieb in "Reason to Believe" classify the following groups as “Breakaways from Judaism” (this list is not written explicitly - it's only my compilation);

• Jewish Idol worshipping sects during second temple
• Hellenized Jews of second temple
• Jews who intermarried during Babylonian exile
• Karaite’s
• Sadducees
• Marranos

He did not mention Islam or Christianity, which I’m assuming means that he doesn’t classify them as “Breakaways from Judaism”.

(He doesn't mention Reform, Conservative, and Reconstructionist etc. because they’re relatively recent).

(R Gottlieb explains in "Reason to Believe" that the reason he added Marranos to the list, is because their approach was against Jewish Law. His purpose is NOT to degrade/look down upon the Marannos, but simply to point out that they did not live according to the Jewish law)

1. What are possible formulations of his definition of “Breakaways from Judaism” based on what he does and doesn’t include in the list?
2. Are there any other groups that I haven’t mentioned yet that ought to be in the list/exceptions?

(See a follow-up discussion here and here)

Answer 1

I ended up receiving an answer to question #1 from R Gottlieb himself;

By a breakaway from Judaism, I mean (A) a group that involves a significant proportion of the Jewish population and (B) competes for the allegiance of the whole population (C) on the grounds that it represents the true original content of the historical religion.

I asked him some follow up questions, and he hasn't yet replied, so I decided to post those question here.

Answer 2

I’m not sure what you are looking for in a list of breakaway OTD groups. There are certainly are plenty of once very successful OTD groups that aren’t on Rabbi Gottliebs list and Islam despite their belief that the Torah was given on Har Sinai did not start as a breakaway group from Judaism. (although very liberal and affluent Muslim societies did spark OTD movements who converted to Islam , claiming that they were convinced of it's truth - see below)

There are too many OTD groups to make a comprehensive list of them so I’ll break them down for you very simply into the two groups that pretty much all OTD groups fell into.

(1)In a society that allowed free entry into the upper middle class, The OTD groups all claimed some variation of “… now that it was discovered… (or) as a truth seeker I just can’t help but acknowledge and realize the truth of...” whatever the intelligentsia of the time and place they found themselves in believed and preached. No difference what that belief was. It actually varies greatly depending on the time and location. E.G Both the American Reform movement on your list and the Hellenized Jews of the second temple on Rabbi Gottleibs list are both saying the same thing adapted for the times.

(2) In places that did not allow free entry into the upper middle class, the OTD groups preached and believed anti establishment political ideologies that falsely promised “this is all the fault of the current Rabbinic or political establishment. When we take over we will change the world”

Some like the Sadducees were a hybrid of the above. From the many OTD groups they can be least described as one of the groups above and I would be inclined to acknowledge that they were from the few exceptions. But they still had those elements. According to Josephus they were primarily from the the upper social and economic echelon of Judean society. They functioned as both a political movement as well as an anti-Rabbinic establishment group. And they existed as an anti-Torah group that could and did only exist in the realm of the specific political, economic and social circumstances they found themselves in. Like all the other OTD groups...