Hello Chickadee, looking at old queries and the only Stanfields turning up in the mid to late 1700 are not in Armagh, a lot in Antrim which is a nearby county so assuming Armagh records are lost or destroyed, we rely on church records at that remove.
Here is a list of C of Ireland records surving, other churches have very few records at that remove.
https://www.ireland.anglican.org/cmsfiles/pdf/AboutUs/library/registers…;
Estate papers or other types of records not online may assist, your could try the Proni site, here too.
https://www.nidirect.gov.uk/campaigns/public-record-office-northern-ire…
Good Luck
Pat