He smiled at me once (at the Haltwhistle train station car park - I was waiting for the schoolbus and he was collecting someone off the train - that's when I knew he was ok). Finding a settlement of roundhouses within the perimeter of a Roman fort is absolutely astounding. Just don't tell him I sold a Roman table fork - the only one of its kind - on eBay for 8.50 last week.

Archaeology is always prone to political interpretation! The loyal Palestinians fled their homelands in the Israeli occupied Golan to rebuild their homes in Israel just behind the "Peace Wall". I'm not so sure...
Society North of the Wall "broke down" during the 3rd Century?
The punatative campaigns of Septimus Severus in Scotland during the early 3rd Century are reflected in a series of huge camps which run up the Dere Street route via Trimontium at Melrose to Cramond (near Edinburgh) which was re-occupied during the time of Severus. A couple of possible Severan camps in Fife. The rebuilding of Carpow near Newburgh on the Tay. A series of vast camps running from there across Angus as far as Durno at Bennachie and beyond.
There is almost no evidence of Severan occupation elsewhere in Scotland at the time. If the roundhouses at Vindolanda were as a result of
"the Roman army providing for these farmers – creating a temporary refuge for the most vulnerable people from north of the wall. Those people may have helped to feed the army and traded with the soldiers, and would have been regarded as traitors and collaborators in the eyes of the rebellious tribes to the north – in what is now Scotland."
then most of the population of Eastern Scotland would be included. There was a vast trade in grain from the whole Eastern Seaboard - what the Roman's called "The grainhouse of the fleet". The people fleeing would have had to march down Dere Srtreet and then head West along the Military Way on Hadrian's Wall for thirty miles to reach Vindolanda. Not impossible... but wouldn't it really be the elites who would have fled? They would have been taken by ship from Carpow, Cramond or Musselburgh surely...

As for round houses built on the sites of Roman Forts. At Inverquarity (North-West of Kirriemuir) there are probably over a dozen roundhouses built on the site of a small Agricolan fortlet as well as a later soutterain built into the ditch of a temporary camp on the same site. Could these imply a group of terrified refugees from England fleeing the loss of their culture and settling in the far North? I think we should be told.