HaLeiVi: It is an old Machlokes between the Rambam and the Geonim. Pashtus is that each Shittah (the Rambam and the Geonim) is untenable if taken to its logical conclusion, thus each Shittah would need a little of the other mixed in. The Or Hachayim’s Derech is certainly not the normative approach in places like Brisk, but it is the easier one to teach to children and therefore is the one we learn when we are very young. The Rambam’s approach strongly disagrees with that Or Hachayim. (And your Ra’aya isn’t a Ra’aya because it’s about a Din D’rabannan and figuring out how the Anshei K’nesses Hag’dolah originally instituted it.)
HaLeiVi: Interesting Maharal. It is against Rishonim, though. See the Ritva on Asmachta (I don’t remember where it is but it’s famous) and the Maharil Likutim Siman 70. The Rambam also has a different approach to Asmachtos.