That there are long lines of unconnected Tweeds is perhaps not surprising, if the origin of the name is many thousands of years old as I hypothesise. Even if all Tweeds in Britain are descended from one family of returned Bretons, the common ancestor may go back to 1200 or even 1100.

Contrary to general statements about surnames in Britain originating in the 1200s for taxation purposes, some family names long precede the "Norman Conquest". Chapman is an English example which has been recorded as early as AD 500.