I think most Yorkies, cotton or silky coated, will do some matting wearing clothes and harnesses. I cut the hair close to the skin under their arms, and very short on the chest and belly. You can also use some type of either PetSilk Liquid Silk to those areas that matt easily.
PetSilk Liquid Silk - PetSilk Products
There is a human grade product that works beautifully on the cotton coats to help prevent matting and that is Hask, Pure Shine Frizz Remedy. I think it's even better at keeping the coat from matts than the Liquid Silk, but I dearly love the Liquid Silk on them and it smells wonderful!