Well, alright, replace 'officially announce civil war' with 'hope to gently dissuade'

The last thing I want to do is pretend to have any authority over who should get what.
My only interest is in seeing this thing work. Really. If the Forsaken is in your domain, he has been there for 40 years, in peace, and the forces actually inside the Hellfurnaces are significantly less than 100
My immediate neighbours to the north are 5 times stronger than me (3 times if somehow the entire Scarlet Brotherhood came to Acererak's defense). He'll just have to row with the oars he's been given. When you're fighting a dragon, maybe it's unfair that you only have 2 arms, but that's the way it is.
Now you two will ally, and whammo, another power greater than just about all the powers of good in the world. I think I can guess your actions in turn 1

Obviously I have some different opinions about this than most, so I'll stop yammering about it, I just hope this whole thing won't have been a wasted effort for 80% of the players.