He is a registered Section C, as is also his sire and dam, so yours might be one that's grown over the 13.2 max allowed for section C's or yours could be out of a D mare? (you don't mention the mare side)
He's 13 (foaled 2007) and I don't recognise much of the breeding till over 4 generations back.
Sorry, am not of much help here except to say Burghwallis Welsh Wizard is full section C breeding on both sides for at least 4 generations.