Which preposition to use with lowlanders

of Occurrences 2%

The earlier of them who went inland partially adopted in the second generation the Gaelic language, laws, and customs; as many non-Celtic Lowlanders of Scotland about the same period adopted the Gaelic language, laws, and customs of the Highlanders.

in Occurrences 1%

A man might have been puzzled as to where all the kilted Highland soldiers whom he had seen at the front came from, if he had not known that the canny Highlanders enlist Lowlanders in kilty regiments.

Which preposition to use with  lowlanders