Lol! Don't be racist - not every Edoan has to look exactly like Arex!
Sigh. Hey, you're the one trying to shoehorn a two-armed, two-legged, eared alien to be the same species as Arex. As I said, there are at least
two Burman aliens in ST IV with more attributes in common with their Kelvin alien.
Obviously you haven't read the "ST Spaceflight Chronology" or "ST Maps", both of which addressed the multi-racial Rigel Colonies. We also saw the human miners of "Mudd's Women" in TOS.
The Rigel Colonies' star, Beta Rigel ("Broken Bow", ENT), should not be confused with the "true" and very distant Rigel (Beta Orionis A), the seventh planet of which is home to the Kaylar ("The Cage", TOS). Remember that "The Cage" infers the ship had a loooong voyage back after fighting the Kaylar.
The term "rigel", IIRC, means "tail" so many constellations can have a "rigel".
Similarly, Deneb Kaitos, the star of Deneb II and V, should not be confused with the "true" Deneb (Alpha Cygni), the fourth planet of which is home to the Bandi and the location of Farpoint Station.