What you read was indeed published, and thus far has ben validated. It seems that the origin of at least 2 of these women was from northern Italy – Lombardy, and is in accord with the history of Charlemagne’s “requesting” some of the established familes of Lucca to move to Mayence/Maintz. Members of the Kalonimus family followed his call.
Conversely, are you still wondering about the multitide of genetic diseases among Ashkenazim?