>> Still, no one is saying that the Merlin of the 6th century is anyone other than the Merlin of the 6th century ~ and he shows up in France, Brittany and Britain. <<
Largely, not disagreeing. But “Merlin’” real name was, to largest extent, Ambrosius Aurenlianus, a person Geoffrey of Monmouth conflated with Merddyn Wyllt. Merddyn certainly is a real person, but the Arthurian legend stuff comes from Ambrosius.
I think that has to do with some missing pages ~ which is one of the great things about the Annals ~ you get to make up so much of it if you really want to.
Even the Round Table is probably an import having arrived with foreign conscripts from the Caucusus in maybe the Second Century ~ it's their story, not that of the Brits, but it sounds so good ~ so exotic ~ and the Brits might well have done something like that except they were divided up into dozens of little principalities barely eking out a life.
Once I found Merlin leading the march into Brittainy, that was it for me even bothering with Ad.
BTW, the only thing I found of genealogical interest to me was when Ad gave away the family estates to the Saxons ~ which is one of the reasons folks moved to Brittany (besides it being devoid of people, cats, dogs, birds, insects ~ the anomaly had been really rugged in that part).