Strictly speaking, huskars aren't a natural subspecies; they were created artificially via gene mods to allow the normally desert-dwelling ausar to live in perpetually cold environments. That said, what you proposed is a solid idea; humans have different ethnicities, so why can't other sapient species have variations, too? There are different variants of rahn, and Olympia mentions that she based her current colour palette off one that's native to Vendiko's south-eastern continent, so there's definitely precedent. Though I'd personally downgrade it from 'subspecies' to 'ethnicities', making the differences largely cosmetic and inherently meaningless.
