In retrospect, I probably shouldn't have referred to it as a legend. That seems to have negative connotations for most people that I didn't mean to convey.
I really don't doubt the authenticity of the story, I mainly was trying to indicate that we don't know when the change occurred but it certainly happened a long time before Caesar: by his day, the change was an oral tradition whose full story was lost in the very distant past.
A legend is a traditional story sometimes regarded as historical but isn't authenticated. You are saying that a legend is a story that is believed to be false. That is exactly opposite from the meaning of the word and is NOT something believed by "all people."
I'm a person, and legend does not have that connotation for me, it means "it was only handed down orally so we can't be sure". I'm sure my idiolect is unusual in that regard, but I stand by my "for most people".
I really don't doubt the authenticity of the story, I mainly was trying to indicate that we don't know when the change occurred but it certainly happened a long time before Caesar: by his day, the change was an oral tradition whose full story was lost in the very distant past.