Okay, sengoku saying that WB is the strongest and has the power to destroy the world does not confirm anything.
I understand the logic.
Sengoku saying that SHANKS has an impregnable team does not confirm anything.
Because in the end it's just a person saying something.
That is why the term "say" applies to everyone.
Buggy said that WB was the strongest pirate, Sengoku the same thing, it's plural people who say (speak).
But you are clearly in trouble ...
after all, if you have two people saying that WB is WSP, it also deserves to be interpreted as (people say).
At the same time you have people telling you to bet on kaido at 1x1. So that clearly negates what Buggy and Sengoku were saying.
So which of the people are right?
In the end kid, killer, sengoku, buggy, and others, are just people saying something.
You can't believe anything in this manga anymore because it's always the characters who say (speak) something.
Your logic is flawed!