I’ve said it a few times before on the forums, but the biggest stand out compared to so many other villain factions in Warcraft’s history is also how specifically sadistic the Iron Horde is/was. Your average Warcraft bad guy will do something bad. Torture a prisoner, kill a civilian, plan to destroy the world. But it’s then essentially limited to that. If you fight them, they will cackle about how you will lose and then try to kill you.
The Iron Horde is very consistently portrayed to absolutely relish in causing as much suffering and mental trauma as possible before even considering killing anyone. In particular towards those who can’t fight back. The average Iron Horde soldier would: 1) Actively seek out an innocent family, torture them in front of eachother and humiliate them as much as possible. Then most likely as painfully as possible, slowly kill the children of the family while the adults watch. 2) Continually mock the survivors while they do everything like this, then as a final mockery, enslave the children’s souls and use them in some foul ritual. 3) Then kill one of the last family survivors, repeat the process again until one person left. This last person would then be kept alive and mocked and tortured on a daily basis until they get bored.
That is the consistent characterization of the Iron Horde. And they do this completely willingly with absolutely no prompting. There’s no dark influence, it’s just something they think is fun.
The only time we see this for the Draenei is in the Mag’har storyline, which again, is from the perspective of some of the most evil villains in the Warcraft universe.
Tbh, we do know that the Lightbound believed that the Mag’har was killing Draenor. And based on absolutely every piece of evidence we have, they were right on that.