Major Discovery

Two or three posts ago I was trying to use Irenaeus' Against the Heresies to prove that the Marcionites and the Marcosians (two early sects that appear frequently in his writings) were related to one another or in fact one and the same community reported in two different ways (or from two different original sources). This would in turn help advance my theory about the unreliability of the writings of the Church Fathers as a guide to early Christianity.
Yet let's forget about my theory about Marcus Julius Agrippa, the last king of Israel for a moment. The passage we cited from Irenaeus is actually massively important on its own.

Who knew that Jesus real name was Yeshu?

Seriously the rabbinic literature is almost never cited as a reliable source for information about early Christianity. Yet here we have an unprecedented AGREEMENT between this tradition and the oldest source in Catholic Christianity (of which we have any direct information).

How many of us knew before I cited this passage that Irenaeus thought "Yeshu" was the original form of Jesus's name? How many of us thought "Yeshu" was orthodox or wasn't a "mistake" or misunderstanding which entered into the writings of the rabbanites?

Yet in a way we SHOULD have known that the rabbinic literature retained knowledge of things forgotten or repressed by the ignorant Gentiles. Look how perfectly the Ben Pandera story is preserved from the early second century (Against Celsus I and II).

Why is my preference for the rabbinic preservation that there was only one Agrippa rather than two so controversial? If the rabbanites can provide us better information about the true identity of someone they considered to be a false messiah (Yeshu) how is it they should be ignored as a source about their last historical monarch and whom they wrote about favorably and many (if not all at one time) took to be the real messiah?