Umbric is a commie pig.
Democracy is boring, so it doesn’t exist.
No faction has a congress or a parliament so you are looking at some pretty stark governments where the people have little to no voice and no representative to make pleas to.
The closest thing to democracy might have been the old Draenei government on Draenor. It was ruled by a Council of Exarchs who voted on issues. The council was comprised of leaders of different groups of Draenei. What is unknown is how the leaders on the Council were selected. Perhaps they got voted in? I have no idea.
https://wow.gamepedia.com/Draenei
Though the draenei rely on the Prophet Velen's leadership and guidance, the administration of the Exiled Ones' society on Draenor was run by the Council of Exarchs. This body, called the "Hand of the Prophet", was formed by the heads of various fields of draenei society and they voted on bureaucratic matters. The Exarch Council consisted of:
Sha'tari Proconsul, representing Shattrath City
Rangari Prime, representing the rangari
Chief Artificer, representing the artificers
High Vindicator, representing the vindicators
Speaker for the Dead, representing the Auchenai
Following the destruction of Draenor and collapse of draenei society, the Exarch Council appears to have become obsolete. The Triumvirate of the Hand may be some form of replacement for it to at least some extent.
The draenei of Shadowmoon Valley were also ruled by prelate administrators.
TO FIX WOW:1. smaller server sizes & server-only LFG awarding satchels, so elite players help others. 2. "helper builds" with loom powers - talent trees so elite players cast buffs on low level players XP gain, HP/mana, regen, damage, etc. 3. "helper ilvl" scoring how much you help others. 4. observer games like in SC to watch/chat (like twitch but with MORE DETAILS & inside the wow UI) 5. guild leagues to compete with rival guilds for progression (with observer mode).6. jackpot world mobs.
As the saying goes, everyone is equal in death, but some are more equal than others.
As far as government forms are concerned, in the Alliance there is a fair mix of monarchical governments (SW and Gilnean humans, dwarves), theocracies (NE and Draenei), traditional feudalism (KT) and a quite restricted form of republic (gnomes), akin to the Italian city-states of the Middle Ages - at least until BfA, when Mekkatorque becomes king.
Horde-wise, you have tribalism (DS trolls, Tauren, Orcs), dictatorship (Forsaken, at least until BfA), traditional monarchy (BEs, Z-trolls), and a budding mageocracy (NB). Vulpera are an odd case, they appear to have a truly democratic government - to an extent.
Finally, pandas appear to have embraced a truly communist/anarchist statu quo.
Except @Samsara got it right. The High King doesn't have unlimited power. They have power only over military matters and even then it's over the troops the member states decided to spare for joint operations. Meanwhile the Horde is an absolute dictatorship.
The Jade Witch always struck me as more insane than actively evil, though you're right in that she's probably the worst Pandaren not actively in thrall to something else. The Sha probably made short work of any Pandaren that might've actually been malevolent, at least prior to their recent collective defeat.
"We're more of the love, blood, and rhetoric school. Well, we can do you blood and love without the rhetoric, and we can do you blood and rhetoric without the love, and we can do you all three concurrent or consecutive. But we can't give you love and rhetoric without the blood. Blood is compulsory. They're all blood, you see." ― Tom Stoppard, Rosencrantz and Guildenstern are Dead
He's a good hearted person who always pursues diplomacy and reason over force when it comes to getting people to follow him but he still seems to be the highest authority in the Alliance.
What does a "high king" do? It's not like Blizzard have ever put it into writing. We can only go off their actions. Yes there's tensions against that authority, but if Shandris' dialogue is any indication he could make the call to kick them out of the Alliance, or at least out of Stormwind, where their refugees are living.
Functionally, the High King is analogous to the Supreme Commander position Anduin Lothar and Turalyon filled in the Second War and the expedition to Draenor. The member nations of the Alliance can contribute forces to the High King's command, but can withdraw that support at any time, as we saw Tyrande do in the lead-up to assaulting Darkshore. Anduin has no authority to require she allocate troops to the Alliance's forces, and Shandris's faction are a breakaway faction who believe in the Alliance (as opposed to Tyrande's... loyalists, I suppose? who are currently fixated on vengeance) and looking to rebuild as best they can.
Anduin can ban people from Stormwind, but he has no authority to kick people out of the Alliance. It's been shown on several occasions that inducting a faction into the Alliance is something the leadership forms a council on and agrees to, unless a given nation is willing to support the other faction entirely on their own (as Stormwind apparently is for the void elves and Tushui pandaren). It stands to reason that booting someone out of the Alliance would similarly require Alliance leadership to convene and make the decision collectively.
Most of Anduin's de-facto power comes from his penchant for interpersonal relationships and the resulting loyalty. Tyrande, Velen, Genn, Jaina, and the others give him, and Varian before him, a lot more leeway than the High King title explicitly provides because they like and respect him, but as Tyrande showed, personal loyalty has its limits and when that limit is hit, he has no power to force her to comply (instead, he had to delay the attack on Dazar'Alor and send adventurers to get the battle at Darkshore over ASAP so he could keep the night elves' support).
Be seeing you guys on Bloodsail Buccaneers NA!