I am not sure from your post that any of the records you mention were from
https://www.scotlandspeople.gov.ukThis is the only site for original Scottish records, it is free to search small fee to view.
CHARLES MCARTHUR Married MARY CAMPBELL 18/12/1808 Kilcalmonell and Kilberry
Children
Kilcalmonell (Birth Records 1777 – 1854) and Kilberry (Birth Records 1824 – 1854)
MARY 1809, JEAN 1811 – only father noted.
ALEXANDER 1813
Kilmeny (Birth Records 1802 – 1854, no marriages)
JAMES 1819, JOHN 1821 & 1823, FLORA 1826
Tyree (Birth records 1766 – 1854)
MARGARET 1830
No death records on any areas above until Statutory Registration 1855.
Given the number of children they had I would expect to see some sort of naming pattern to their parents, the one you mention, below, does not reflect that. They had two boys named John, so I guess that name was important to them. I would not have thought there would be a marriage for a child the age of 12 to marry in Scotland, even though it was possible it was not common practice.
MCARTHUR CHARLES DUNCAN MCARTHUR/EFFIE MCLELLAN 26/04/1783 South Knapdale
Scottish Naming Pattern.
First son was named after his father's father
Second son was named after his mother's father
Third son was named after his father
First daughter was named for her mother's mother
Second daughter was named for her father's mother
Third daughter was named after her mother
Other daughters were named after other family members
Don't be misled into thinking that any of this is a hard and fast rule.
Colin