1. Some scholars have quetioned the historicity of the garudhamma.
2. The relationship between the male sangha and the female sangha (not between monks and nuns) could be compared to elder brother and younger sister. Its relationship is not about superiority, but seniority. An arahant who has less vassa than a normal monk would still have to walk behind him.
3. Some of the rules were formulated for the protections of the nuns, and some are formulated at the request of nuns themselves (ie having complained about a cetain nuns' behavior). There is also a rule that a nun is should not attend a bhikkhu with water or fan when he is eating (Pacittiyas 6).
Best wishes,
Rahula
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