I have been having trouble finding a good location for setting the story "The Mound" from Thrice Told Tales in Scotland. My troupe's covenant is set in the Galloway Hills in SW Scotland and I was looking for something in area between Argyl and the Borders. More problematic than finding a bog in Scotland (Duh!) is identifying 2 feuding neighbors. I do not want it set in Galloway since the story has already overturned history with Alan Lord of Galloway slain by a Faerie Queen's knights thanks to a story from Hooks. I think the Scoti could have imported Crom Dubh so I am cool with that aspect of the tale.
Feuds shouldn't be difficult to find in medieval Scotland. Most of the information we have about the Border Reivers and clan feuding is from 1500s-1700s, but most of the clans have origin stories which extend back to the 13th century and earlier. It is not a huge stretch to have the same feuds in operation in the thirteenth century as existed a few hundred years later. In period, clans held lands as 'thanes'. Scotland only had a few barons at this time, and those in the Borders held their land in regality rather than as tenants of the king; so the thanes fulfilled the function of the lesser nobility (landed knights and lesser barons) in other lands.
For a specific example: immediately outside Galloway in Annandale and Strathnith, you've got the Armstrongs (rivals of Bells and Johnstones), Bells (rivals of Irvines and Armstrongs), Irvine (rivals of Bells and Maxwells), the Johnstones (rivals of Armstrongs and Maxwells), and the Maxwells (rivals of the Irvines and the Johnstones). And that's just a tiny fraction of the full border rivalries, especially once you include the cross-border feuds. With the exception of the Irvines, the clans just mentioned were all members of "The De'il's Dozen", thirteen notorious Scottish and English families responsible for the majority of the clan warfare.
The Maxwells, in the 13th century, were a baronial family holding Caerlaverock, and were also the sheriffs of Roxburgh. The Irvines were close allies of the Brus family which ruled the barony of Annandale. This makes them, and perhaps the Irvines, ideal replacements for the two baronial families in The Mound.