You know, I've found it a bit strange how in Beyond the Dark Portal it introduced 7 new orc clans(excluding the Flowerpickers) but the human kingdoms remained the same.
How would you introduce new human factions there?
Since it's set on Draenor they might not be kingdoms but maybe like colonial factions.

I was thinking, since in WC2 each color is associated with a certain kingdom or clan, how I'd do the same for night elves and undead.

Night Elves:
>Blue
Sentinels
>White
Elune Priesthood
>Red
Watchers
>Green
Corrupted Ancients
>Black
Night Warriors
>Violet
idk
>Orange
idk
>Yellow
Kaldorei Traitors

Undead:
>Blue
Forsaken
>White
>Red
Tichondrius' Undead
>Green
Kel'Thuzad's Scourge
>Black
Ner'zhul's Scourge
>Violet
Arthas' Scourge
>Orange
idk
>Yellow
Undead Traitors