The rules are just rough outlines for the sith, created to suit the situation in their respective time frame, everything beyond just comes down to the individual philosophical views of a sith.
Abyss master, Darth Ophidia for example seeked a bit of both, having many sith because of the wider effect range of many sith working together, but she still believed that an apprentice has to kill the master at some point to guarantee that the next generation of sith is stronger than those before.
Abyss himself objects all rules to some degree, but aligns mostly to the Ro2, but also believes in the as you called it "anarchy". He doesn't wish to serve in a unified sith order, but rather wishes for individual small groups of two (or maybe more each to their own) that work loosely if at all together and mainly care for their own goals.
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