The zed in MacKenzie is actually a yogh. Zed was only found in foreign words such as zeal in the 16th century, and the surname Menzies has the same problem, which is why Charlie's ancestors changed the spelling to Mingus. In later Scots, the spelling was changed to "y" apart from proper names. The Gaelic spelling is MacCoinneach, pronounced (approximately) mac Kunyoch.