You put too many characters in one choice.
There are characters with either authority or specific knowledge in the OP world who are more believable, then there are those who are used for a particular introduction but the info may or may not be credible, Buggy for instance, or Yosaku.
Yosaku gave us the info about Shichibukai for instance as a tool of the writer, but at the same time fed us a lie with Jinbe, something Oda does quite often, introduce something by a third party, and then reveal it´s actually a bit different.