That’s interesting; I’d imagine the main difference would be stuffing ingredients available. I’ve seen similar things with different names, but the pasties I’ve gotten resemble a large empanada (almost a foot long). Some of the ingredients resemble what you’d have in shepherds pie.
I didn’t sample the Devon pasties (none available in Cornwall), but the locals said you can tell a Devon pasty from a Cornish one by looking at the crease. The Cornish pasties are creased on top while the Devon pasties are creased on the side.