I agree that Rayleigh is not a benchmark/comparison for Zoro in any way put forth by the story, but the assertion that Shanks/Rayleigh (or whoever else)>EoS Zoro is unjustified.
The logic on this does not follow and has easy holes:
PK goal>WSS goal => Rayleigh>Mihawk
Personal strength does not dictate one's capacity, effort, or willingness to teach haki techniques. Ivankov and Sanji's goal is also far below Mihawk/Zoro's in terms of personal strength, but Sanji is not far below Zoro in personal strength. Mihawk's status as WSS and Rayleigh's status as a swordsman makes Mihawk>=Rayleigh easily plausible and probable.
You also have circular logic here with no initial justification (one is being used to support the other and back again).
Shanks/Rayleigh/Oden>Mihawk => all "top" conquerors>non-conquerors => Shanks/Rayleigh/Oden>Mihawk
The story makes Mihawk>=Shanks/Rayleigh/Oden plausible and probable by the WSS title alone until further reveals or contextual information on the title. Not to mention the arbitrariness of designating "top" conquerors as opposed to...like what, middling ones like Chinjao? Seems like you're just selecting your goal post here based on your feelings. Is Katakuri in or not in this elite circlejerk of characters in your head?
Plus you made a lot of assumptions about the strength levels of other characters in comparison to each other when we don't even have information about them (Scopper to Rayleigh, Jozu to Marco, Queen to King).
All in all 3/10 analysis. A+ for putting an effort into justifying the head canon you've dug your heels into over the years, but ultimately an F for having anything substantial to them.