Dufagan, 1st Mórmaer of Angus - Dubacan mac Indrechtaich?

I would suggest that this is "Dubacan of Angus (Medieval Gaelic: Dubacan mac Indrechtaich) is usually regarded as one of the earliest attested Mormaers. He is mentioned as Dubucan filius Indrechtaig mormair Oengusa (i.e. "Dubucan son of Indrechtach, Mormaer of Angus") in the Chronicle of the Kings of Alba, and it is told that he died along with his lord, Amlaib, son of Caustantín II at the Battle of Brunanburh (c. 937)."https://en.wikipedia.org/wiki/Dubacan_of_Angus

and that, once he's been detached from the Dufagan who is (by 'tradition') Mormaer of Fife, there needs to be some proof that he really is the brother of Gille Míchéil MacDuff, Earl of Fife as he is presently shown.