Just browsing through Faith and Flame, and found reference to Maugris of Diedne. Can't blame the authors for co-opting this character from The Matter of France. Though the tales said he aided his cousins in rebellion against Charlemagne, nothing about Maugris being Court Wizard.
Does sort of contradicr my Saga where I had him as an almost Founder, who broke with Bonisagus due to the recruitment of Diedne, and the other Founders approval of Charlemagne.
Perhaps I can say that there were two wizards of very similar names that got conflated in the tales and histories.
Now I am worried that I will find Atlantes in canon material.