Well, me being more into making felines. Don't get me wrong I do have canine characters to. But I believe that it is to do with that Feral-heart has the Husky and German Shepard markings. And others don't tend to use the other markings to create and/or represent another breed of dog. As often as German Shepards etc. And I also tend to think is that people can be scared of making mistakes. But, they shouldn't be. As if they wanted to make a different breed. But couldn't think on what markings to use. And so on and so on. Which is why I believe those two canines are most common.