You said inquisition was right in your original post Edit: Was why I put the link so you could see it was the wolves who were right
No they where right about chaos spreading though the IG forces. thought they still should have lived.
I might be cherry picking canon because of He-who-must-not-be-named but In my opinion Gazghkull Thrakka gets killed first as the odd man out, since he would swing at everybody equally. (though in 1v1s i wouldn't know where to place him, and I'm not quite sure he can 1v3 could be wrong though) Marneus Calgar would probably be the second to fall, ignoring the plot armor, (anything short of a primarch killing greater demons/avatars in single combat seems like BS to me) chief smurf or not, hes still an Astartes and hes already got his ass kicked by the swarmlord, (yet an avatar was no prob?) and again when he lost his limbs. (which was a minor skirmish i think?) That leaves Eldrad vs Abbadon, but didn't Eldrad beat Abbadon 1v1 in White Dwarf 266 A Clash Of Titans?( not sure if Canon or not) Haven't personally read it but it came up in a discussion once, (quick Google gave me the name) in that story if the Chaos gods didn't save Abbadon he would have died. So Eldrad has the advantage of already beating Abbadon once before. I do think Abbadon has more straight up power though.
What if Commander Farsight(me ), who hates the Ork's guts was to face Gazghkull? I mean, in lore, Orks actually somewhat fear Commander Farsight But on topic: Eldrad...because he would forsee it all. Darn magic.
Yes. But it's Ghazgul. The one that gets the 2++ Inv, crapton of attacks and has the massive power klaw? Seriously commander, I would really advise keeping at range for this one.