Hi Steve,
"Sa group" was quoted from Hawley's...
Probably in this context Hawley is using the word "group" as "school" or lineage.
He lists Mitsufusa from Aki as MIT 30, and 2 Aki smiths named "Sa' 1394 and 1441, SA 7 and SA 8.
There was a smith now known as "O Sa" who founded the Cikuzen Sa School, who was supposedly a student of Masamune. Not, as far as I know, related to the Aki bunch; Hawley lists him as SA 11.
Hope this helps. BTW I'm using the "Commemorative Centenary Edition" (2 vol set) of Hawley's. Don't know if that makes a difference or not - I'm kinda new at this.
Regards,
Dan K.