It seems to be becoming clear from the very wide distribution of some surnames in early records that they are not all patronymics. In my opinion this includes Clague, Clucas, Corlett, Corkill, Kelly. These variously could derive from ethnicity, location and status.
The status of people with 'Mac Gil' names is of considerable interest, it seems likely that they were not to be classed as freemen, but were tied in some way to another named family or ethnic grouping.

A proportion of names do appear to relate to place-names, and some may be of a single lineage. I suspect Kinvig is derived from Dun Beg (little fort). Cojeen apparently from Faaie Dun (the green belonging to the fort).

There is the issue of successive waves of settlers, the late arrivals from the Western Isles may have been very mixed in ethnicity. It is hoped that the landscape origins can eventually be linked to surnames as well as DNA, the correct outcome will be wholly compatible with each source of data.