I've come across this John Cruickshank before. In 1841 he was at Newton, Rothes, aged 79, with (presumably) wife Jean, 75 and (also presumably) son Thomas, 37. John was born in Morayshire but Jean and Thomas were not.
I am fairly sure that these are John C and Jean Dow, who were married in Mortlach in 1799 and whose son Thomas was baptised in Mortlach in 1802. There was also a daughter Margaret, baptised in 1800. Thomas died in the woods at Drumbain in 1876 after apparently getting lost while out cutting brushwood.
The records of the neighbouring parish of Knockando were destroyed by fire in the late 18th century, and I suspect that most of the Cruickshanks in Rothes, including my own 4th-great-grandfather Alexander Cruickshank, had come into the parish from Knockando.
There is, apparently, a book 'The Cruickshank Family in Strathspey and Stracathro', by E G G Cruickshank and W Gordon, published in Elgin in 1847. This does seem to suggest that Alexander C of Stracathro may have been a descendant of a family in Morayshire. However neither Moray Libraries nor the National Library of Scotland appears to have a copy.
There is also a book 'Historic Footmarks in Stracathro', by F Cruickshank, published in Brechin in 1891. This was the Rev Frederick Cruickshank, minister of Navar and Lethnot in Angus from 1854 to 1905. He was the son of William Cruickshank, a weaver in Kirriemuir, and his wife Janet Muir.
According to A J Warden's 'Angus or Forfarshire', Stracathro was bought by Patrick Cruickshank some time before 1775. He had five daughters but apparently no sons, and after his death 'the property was acquired by their uncle, Alexander Cruickshank', and his trustees sold it in 1848 (Vol V, p169).
However in Vol III, page 184 Warden says that the Cruickshanks of Stracathro were members of the family who also purchased Langley Park, Keithock, Glenskenno and others.
"Andrew Cruickshank married a daughter of Bailie of Dunean, by who he had two sons, Donald and Thomas.
Donald Cruickshank of Gorton married Catherine, daughter of John Grant of Auchterblair, and left issue: James of Langley Park; Patrick of Stracathro; Charles, Capt HEICS, slain in 1793; St Vincent; Alexander of Stracathro; and daughters: Clementina, married to Rev Mr Grant; Jane, married to James Houston; and two sons and one daughter who died young." He goes on to list the descendants of James of Langley Park, but says nothing more about Alexander of Stracathro.
(There's a marriage of a Clementina Cruickshank to Robert Grant in Cromdale Inverallan and Advie in 1811, but he was a weaver, not a reverend.)
There's a gravestone in Stracathro commemorating Donald Cruikshank of Gorton and his wife Catherine Grant, both interred in Strathspey; their first son James of Langley Park (1748-1830) and his wife Margaret Helen Gerard; their second son Patrick of Stracathro (1749-1797) and his three wives, and a grandson. Apparently there are related stones in Inverallan and in Cromdale, but I don't happen to have that book of MIs.
(If Alexander was 74 when he died in 1846, he must have been born in 1771/1772, which is over 20 years after his brother Patrick?)