Hi Donna,
I think you are right that William Kermeen & Jane Costean were from Ballagorry Maughold, and that their son John was ch 18 Jul 1813, but he was too young to have also been the Cardle one (who married Isabella Cleator in 1825).
Where did you get the idea that Ballagorry John Kermeen was also of Cardle Voar? There were a LOT of John Kermeens!
In the 1841 Maughold census (rounded adult ages):
3 6 20 Ballagorry
Jane KERMEEN 60 Isle of Man (Costean?)
John KERMEEN 25 Isle of Man (presumably her son bapt 1813)
James KERMEEN 15 Isle of Man
Margaret GARRETT 6 Isle of Man
3 3 10 Cardlevoar
John KERMEEN 35 Isle of Man (aged 47 in 1851)
Isabella KERMEEN 35 Isle of Man (Cleator)
John KERMEEN junr 15 Isle of Man
Robert KERMEEN 10 Isle of Man
Cathrine KERMEEN 8 Isle of Man (married Daniel LOWEY 10 Jun 1854)
James KERMEEN 1 Isle of Man
Sue