Coyote are not are not wolves are not Shelties are not Beagles. And the genetic differences are a result of genetic reduction, ie Shelties lack the genes to breed Beagle-like (morphologically) offspring but they are all the same ‘species’ genetically. Taxonomy is not an exact science.
Reality doesn’ t always conform to the nice neat boxes that people want to segregate them into, but even the most extreme lumper taxonomist doesn’t classify wolves and coyotes as the same species. Inability to easily reproduce together is a possible effect of a long reproductive separation. It is not what defines species.