Unverified Griffin Family History

The show: Family Guy
The episode: "Peter's Progress," first aired on FOX this past Sunday.
What happened: Cleveland introduces his cousin Claude, who claims to be a psychic. Claude tells Peter Griffin that his ancestor Griffin Peterson is the true founder of the Quahog colony, way back in either 1670 or 1760, contradicting the myth of chatty Miles Musket and the Clam (which Quagmire cites). Claude tells the story of how Griffin Peterson fell in love with Lady Redbush (who looks a lot like Lois) and asked her to marry him. Lady Redbush said yes, but King Stewart III (who looks like Stewie) decided he wanted Redbush for himself and sent Peterson off to the British colonies in America. His shipmates include versions of Joe Swanson and Quagmire. They land in what would become Rhode Island.
Why it makes no sense: Since when are psychics historians? Watch an episode of Medium: Allison Dubois tells fairly recent history, such as someone having been killed a couple of years ago, and not pre-Revolutionary War history. A psychic is supposed to read what is in someone's mind, and apparently this whole story of Griffin Peterson and the true founding of Quahog was news to Peter. If Claude really was reading Peter's mind, shouldn't she have come up with a story much like the one Peter told in "Untitled Griffin Family History"?
I'm perfectly OK with the Miles Musket story (from "Fifteen Minutes of Shame") being either a complete fabrication of Adam West's, or a commonly accepted myth (like Benjamin Franklin flying a kite in a thunderstorm). But it's not OK to rewrite Peter's genealogy because there is so much material already, a lot of it a lot more reliable than some random new character. This latest rewrite of Quahog history can't be taken seriously because it makes no sense and it can't be taken humorously because it's not funny. I watched the whole episode and laughed only once, at Brian announcing new shows on FOX, and even that must've been me being generous.
In fact, the Griffin history given in "Untitled Griffin Family History" is a thousand times better: it can be taken seriously, because it builds on previously established continuity, namely the story of Nate Griffin, the slave owned by the Pewterschmidts and given credence by historical records Peter found at the library and which were convincing enough for Carter Pewterschmidt to pay Peter reparations (in the episode "Peter; and it can be taken humorously because it actually was funny (at least to me).
In conclusion, this was a boring episode with little laughs and no usable continuity.