Yes you're right they used bull blood in Heide breeding program as the Working Wheaten terrier of Ireland (Staffordshire / BT X Wheaton ) Heide is good for boar hunting as Working Wheaten for badger drawing .. about smaller working breeds I prefer the Jagd over Patterdales - Plummers - Parson Russel or fox terriers . About your new pup F1 Airedale X Jagd cross it could result a good working dog .. stronger than pure bred jagd and the best pet companion of your son for sure ! good luck with Rowdy Regards