Canon Quine (he of of the unquenchable belief in a Roman occupation of Man) had a theory about the clan system - see www.manxnotebook.com/iomnhas/v01p053.htm
The late Rex Kissack had a go - see www.manxnotebook.com/famhist/v01n1.htm#9-14 as did the famous PMC Kermode see www.manxnotebook.com/iomnhas/v01p477.htm