a list that has a John Dalrymple as Governor of British Mauritius. There are enough John Dalrymples to allow for a disambiguation page.
When there are multiple people with the same name, it is important to exclude the ones that do not fit. A date of birth and death is relevant. The time of having been governor is from 10 December 1818 to 6 February 1819 and that excludes most of them.
There is only one likely candidate; the eight earl of Stair. There is no source but hey, it is at least likely; one source describes the governor as a general and, this one certainly was one. I am however not sure.
There is a Listeria list of British Governors. When someone knows better, he can adapt Wikidata and everywhere where the list is used things will improve.