One of my best commenters, R Berel "The Yerushalmi (Sheviis 6:1, 36c) records a tradition that when Yehoshua came to conquer the land he gave the inhabitants the choice of war or leaving and one nation (Girgashi) "believed in Hashem" and left for Afriki."
"I wonder if this in some way reflects a tradition about the Punics. "
This called to mind Tosefta Shabbos 8, 12:
י[ר"ש בן גמליאל] אומר אין לך בכל עממין מתון יותר מאמוריים וכן מצינו שהאמינו במקום [דגלו] לאפריקי ונתן להם המקום ארץ שיפה כארצם והיתה א"י [נקרית] על שמן:י
(I am not a textual expert, so I am not going to try to make sense of the brackets!)
This in turn called to mind a future post I was planning, about an alleged Punic inscription mentioned by the 6th century Byzantine historian Procopius which was said to have been made by Phoenicians who had fled Canaan long before and, he said, could be seen in his time.
We have it in Greek translation, and it read: ημεις εσμεν οι φευγοντες απο προσωπου Ιησου του ληστου υιου Ναυη. Which does indeed means something like "We are those who fled before the face of Joshua, the robber, the son of Nun."
Not that I need to tell you, but it's good for posterity, in the Latin alphabet ληστου is listoi--ליסטא.
Of course a testimonial from the 6th century doesn't tell us if this inscription is authentic. Indeed, by the 6th century Christianity had spread the story of the Bible far and wide, and the inscription--if it existed--could have been a fraud intended to corroborate the Bible (or it is authentic and ancient). But what it does tell us is that this idea, found in our rabbinic sources, was not only in Jewish sources but was widespread.
It seems the Canaanite provenance of the Punics was not only widely known but an issue vis a vis relations with Jews.