Following the advice of @ColeValleyGirl in an earlier answer I now think I may know what transpired.
The only Angove baptism in the 18th century at Gwithian was, from the Cornwall OPC record 1358612 in the Baptisms database:
Day Month 09-Mar
Parish Or Reg District Gwithian
Father Forename William
Mother Forename Elizabeth
Transcriber Kathie Weigel
This occurred under the Julian calendar so it was 4 months after the marriage of William and Elizabeth, and was in William's parish so it looks like a pregnancy may have necessitated a quick marriage in a nearby parish.
At the time Gwythian marriages were very rare:
John Petherick of Phillack & Jane Cock 23 February by banns
1748 -- none
1749 -- none
James Hoskin & Mary Hoskin 31 December by banns
Ralph Clements of the Parish of Gwyniar & Mary Cock 31 Dec. by banns
1751 -- none
1752 -- none
Ambrose Blackwell of Phillack & Grace Hockin 5 Feb. by license
John Verrant of Illogan & Jane Crase 22 May by banns
Henry Johns of Phillack & Catharine Hockin 13 August by license
I suspect that they chose to marry in the nearby Phillack parish rather than travel further to Elizabeth's parish of Illogan for both expediency and privacy.
Curiously, only one other Angove marriage occurred at Phillack between 1700 and 1750:
The Cornwall OPC currently has this as record 388182 in the Marriages database
Day Month 09-Feb
Parish Or Reg District Phillack
Groom Fn Abel
Groom Sn ANGOVE
Groom Rank Profession gent.
Bride Fn Jane
Bride Sn PHILLIPS, Mrs.
Transcriber Notes Phillimores
Transcriber John Smith
William and Elizabeth named their sons William, William, John, John, Abel and Thomas, in that order. I have not yet found a solid explanation for why they may have named a son Abel after a wealthy namesake, who does not appear to be closely related, other than perhaps for luck.
There were some other Hocking marriages at Phillack between 1700 and 1750:
1739 Phillack Thomas WITHIEL Grace HOCKIN
1738 Phillack Francis HARRIS Jane HOCKIN
1720 Phillack Henry HOOPER Katherine HOCKIN
1739 Phillack Hannibal TREDINICK Jane HOCKIN
Unfortunately, I have not yet identified the parents or siblings of Elizabeth. She and William named their daughters Elizabeth and Mary, in that order.