Technically I don't think you should be able to reach a consensus, because it depends on how you lived your life, but a culture can greatly influence a race or group to go a certain way.
Where do you think each race would have most of their members? Feel free to include certain periods where a race changed a lot and behaved differently, influencing their shadowlands covenant.
e.g. High Elves: Kyrian up till the scourge invasion.
Blood elves: Revendreth for most deaths afterwards
Night elves: Revendreth, Kyrians and Night Fae for the millions that died in the first invasion of the legion (remember these weren't the evil night elves)
Revendreth and the Maw for the Zin'Azshari highborne, naga, satyr who were slaughtered by the kaldorei resistance
Night Fae for the NElves who died in WC3
Orcs: Pre horde: Night Fae and Maldraxxus
Horde era: Maldraxxus and the Maw
New Horde era: Maldraxxus mainly
That sort of thing: Frankly I think humans are the only ones that could literally go in any covenant, the other races are too shoe horned in one aspect.