Personally, apart from them both being non-human characters, I find them quite different in concept overall, and do not think it would pose much of a problem to have them both. I think Atrayen would provide a broader perspective of the universe as well, hinting towards actual relations between human and non human races beyond mere individuals. In typical stories with settings like this, you always just see one character from another race acting as a hero for a people rather than any actual discourse between the two cultures, aside from the occasional aquaman UN joke. Having an isolated species with real, albeit scarce, interaction with the actual human population seem like it would make the narrative much richer by its presence alone.