From what I can see there’s something along the lines of:
(Lord) Illidan
The Slayer
Enforcers (Guards)
Maybe a scout rank
Allies (Naga/Broken/Demons with their own power structures)
(Formerly) Slaves
But I am struggling to find any kind of real information on how the whole shebang was organised. Or did the Illidari basically just hang out and do whatever according to their own agendas? I know Kor’vas wandered off a few times to do her own thing after all.
I think there were a handful of elves at the top spearheading the operation; Illidan/Slayer and a few that sort of made up the council of you want to call it that - Kane, Korvas, Allari and Jace.
The rest were just generic demon hunters following the orders of the aforementioned I guess
Are Illidari even able to leave the organisation? What about the current Kaldorei and Blood Elf Demon Hunters fighting each other because they joined the other faction?
It’s important to understand that the Illidari was more a rough term used to describe forces loyal to Lord Illidan.
The Fel Orcs, Demons, Blood Elves and Naga fell under that; but they were also their own armies with their own internal ranks and organizational structure separate from one-another. And then the Demon Hunters came as a fledgeling organization after Illidan had established himself on Outland.
Think of it as a military coalition of very different armies.
It wasn’t until the Demon Hunters who came into the fore at Legion that we got something close to a pure Illidari organization, but the Demon Hunters only number in a few thousand, their organization was formed ad hoc and is still very young. This, combined with the fact that Illidari are generally specialists who go off in smaller packs or solo, or embeds themselves with other bigger units; as opposed to fighting in ranks and armies; explains the general lack of a ranking system.
If the Illidari is not split by the faction conflict and endures, I imagine we’ll see a ranking system be slowly expanded with the decades. This is usually how organizations develop.
Right now the Illidari is pretty small.
They have lost access to Fel Orcs; it is unknown whether the Naga will remain with them in the future; the broken are limited in number and require going all the way back to Outland to train new, and the Blood Elves army units are long gone.
Essentially the only reliable source of military units for the Illidari right now, aside from Demon Hunters, is ironically enough demons, mostly their shivarra.