So In tes there aren't simply nine races. Ignoring things like snow elves, aylieds, sloads and other stuff we've never played before; the Races we have played aren't just one ethnic group. This thread isn't a suggestion but a question: would you like to play a giant sentient Tiger?
For starters there Many, many types of khajiit. A few are quadropedal (four legged. I'd assume we're not playing those, but feel free to disagree). There are huge khajiit geared towards combat, The average sized bipedal Khajiit for more agile characters, and one special breed of Khajiit that are small and very good with magic (think Cat-Yoda). There are breeds which are full cat, breeds that are very cat (think awkward legs from morrowind) breeds that are more humanoid (Normal shaped legs. Oblivion and skyrim Khajiit) and one breed that's almost indistinguishable from bosmer.
(breed is dictated not by your parents, but chosen by what phase of the two moons you're born under. The Khajiit that looks like a bosmer could totaly give birth to a khajiit that looks like a Gigantic tiger.)
The argonians have an unknown amount of variants. Their level of argonian-ness is dictated by how much tree sap they've drunk. (maybe all people have the capacity to become argonians? ) Anyhow, They create different racial tribes. Think of every lizard; Iguana, Bearded dragon, Thorny devil, chameleon, agama, blue tongue, komodo... even throw in a few amphibians and fish in their (angler argonians. Oh Aedra save us...) Along with some bird like argonians, snake like argonians (They still have legs though)... and so on. Whilst a lot of this would be cosmetic, there's still some features that would make gameplay differences. Some breeds are pretty big and might be unlike the frail argonians we're used to. Some natural features might be usable; A big mouth with sharp teeth could be deadly, natural poisons could be accumulated, Horns could be used, and spikes could discourage grappling (and probably make some body armour more awkward to wear)
Imperials are supposed to have two ethnic groups to them. No Idea on racial differences for that. Morrowind and Hammerfell have some differences between coastal/civilized people and wastelanders (but all morrowind males have the smokey voice that Jiub has and that is fact don't tell me otherwise nahnahnah can't read you). I'm sure there are others that I'm forgetting.
Anyhow. Would you like to play as a giant cat, poison-factory toad man, Humanoid Velociraptor, Genuine ashlander or distinctly southern Imperial?