Memorial inscriptions:
Langholm Auld Kirkyard: one Broatch: (ROBERT BROATCH who died in Langholm 16th May 1844 aged 67 years)
Wauchope: one: (MARGARET MILLAR wife of Thomas Broatch who died 16 December 1911 aged 59 years ~ no mention of Thomas)
Westerkirk: one burial in 1959
None in Ewes, Staplegordon, Eskdalemuir, Canonbie, Castleton, Ettleton or Unthank graveyards
~ so Broatch isn't a common name in Eskdale or Liddesdale, unlike Elliot.
You might get an idea of the distribution of present day Broatches using the on-line telephone directories.
WalterC