in the sense you describe there were no clan systems on the Island (at least within recorded history) - there were powerful families (see www.manxnotebook.com/iomnhas/v01p053.htm for one take on this 'clan' nature). Don't forget the Island was actually at the centre of the Irish sea basin region based on sea transport rather than land holding and was a cosmopolitan as any motorway service station is today - today's histories relegate the Island to the periphery but before the 13th C it was the centre and the peripheral areas were the adjacent isalnds with poor road systems