See my updated pedigree in my first reply in this topic. Originally I only had 6 sons for Lorccán, but reexamination of the text makes it seem likely that Macc Liacc [son of (a) stone] was the seventh son.
https://genelach.network/transcript-boo ... uachGalaig
902. Seacht mc. la Lorcan mc. Conaing mc. Cormaic Fergusa cnoc .i. Niall Cuchluana Maeleidigh (no Maelmithigh) Conaing Ceannfaelad Geimhredhan. Dibaidh tra Sil Lorcan gein mota ri Geimhredhan gona sil & is ed fodera doib sein Mc. Liag do beannaigh Lorcan is do sin asbert Mc. Liag:
Lorcan lasadh isan ath
co fobhair cath i cath cruaidh
doni Lorcan gongail ngaith
dlochtan do cinn laeic goluat
I do want to emphasize again that the length of that pedigree for Ernán's descendants makes it VERY unusual for a non-chieftain line.
Also, I think that same pedigree for the Mac Diarmata is given somewhere else besides Durning, but I cannot recall where. Regardless, I think the best evidence so far indicates it is a bad pedigree and the one you reference is correct. Further, O’Hart is the only place I can find that has Sioda as a son of A Diarmait, but not THE Diarmait. His MacDermot pedigree seems to be notably erroneous.
https://www.libraryireland.com/Pedigree ... eremon.php
https://www.libraryireland.com/Pedigree ... eremon.php