Their was a very prominent family in Lancashire, England just south of England. It belonged to Sir Osbern Gardner and he has numerous descendants. Sir Thomas Gardner was a knight and was a descendant of him. He probably has numerous descendants all over the world.
I guess most people have trouble determining where they came from because people migrated.
I can see why living on the Isle of Man or on the Scottish border would make you consider yourself all of the above, and I guess the Gardners were all of the above with all the English, Scotch - Irish and Welsh.
Their was a Syr Wyllym Gardynyr, the Knight, who was Welsh and reportedly killed King Richard III at the Battle of Bosworth. He was from that Gardner family. The famous Lion Gardiner is also from that family.