The link connectio as is works back to him being son of his dradaughter
Erispoë I "the Elder" de Broërec, Comte de Poher MP
Son of Budic de Poher, Roi du Bretagne and Marmoëc de Poher
https://www.geni.com/people/Marmoëc-de-Poher/6000000003827963746 MP
Birth: circa 810
Nantes, Loire-Atlantique, Pays de la Loire, France
Managed by: Patricia Ann Topping
Daughter of Riwallon III, count of Poher and N.N. Lahngau
Wife of Budic de Poher, Roi du Bretagne and Erispoë II, king of Brittany
I'm sure you have come across names repeating. The granddaughter and the mother probably carry the same name and along the way dates were incorrectly attributed by a very excited individual. a little digging into ARCHIVES.Com or History of that era will turn up more information. Sometimes, I've found, common sense wins out. You may also discover that a whole generation is missing. I'm not a pro, but He's on my chart and I'm sure I've muddled through somehow to go back even further.