I recognize that the companions system will start with a limited selection. In an anthropocentric world, human and mer companions are understandable as first choices. I’m excited to meet the two we’ve seen so far.
For down the line, ZOS, if you do create others, please consider a Senche-Raht. Meeting them was one of the highlights of Elsweyr for me, especially Sanzagh (who is still deliciously bitter over not being allowed to eat Gordon the Guar). I’d enjoy having one as a battle companion, as they are said and shown to be in game.