What dates do you have for your oldie barns and where are they located ?
I echo Jim's request to see some pics of your finds.
You might find it worthwhile to browse the pages of "Discovering Timber-Framed Buildings" by Richard Harris where the English system of framing (long walls and cross frames) is explained.
Though one can generalise there are always exceptions to the rule to be found and I can think of at least one early (1390's)building in Farnham, Surrey, England that exhibits interrupted wall plates but this building is surrounded by many others that have continuous wall plates.
Specific problems will demand exceptional design solutions but that exception does not make it a rule.
