My players are so smart, I like to let them to a lot of my work.
It is my habit to do periodic e-mail infodumps (saves talking head time in the game and gives players hard copy to refer to), which always include a lot of extra stuff which I don't expect the players to deal with directly, just to create a sense that the world does not center on them and to give NPCs other things to do than fulfill the campaign objective, so that the PCs become the logical person to do the job. If they get more interested in the alternate problem, well, that can work, too. Far be it from me to make people tackle a problem that doesn't interest them.
So, for various reasons the PCs got to Brindol after the Horde's started moving but before it would be appropriate to run the council meeting in the book. So they report on what they were doing and hear the reports from the other people, for the purpose of which I went through the town stats at the front of the book and figured out how the population of each town would behave, and integrated this news into the meeting. Reading about Baron Trask and his brigand sons, I realized that this was the perfect time to make a landgrab - Brindol, the closest thing to a regulatory agency in the Vale, can't possibly spare personnel to deal with Trask's power bid, and in fact if he takes over Red Rock and Marthton, reducing the first town to order and using the treasury of the second for military purposes, he'd make a better ally than either of the existing governments, except for being an imperialist creep. So he makes his move and the council is arguing how to respond, when one of my players pipes up (note that the BBEG is a duergar intent on conquering people, then using them to conquer more people):
If you'll pardon my interruption, Red Rock sounds like just the sort of community the duergar are interested in. What are the chances Trask seized Red Rock with the idea of selling it to the duergar for Elsircross's freedom? Or that the orcs of Red Rock will accept Trask's aid only to sell him out when the Red Hand arrives? He knows Brindol doesn't dare commit troops, but he also knows if Brindol survives the war he'll be punished for taking the opportunity to seize the mines. If you consult the map we have, Red Rock and Elsircross don't have notations about plunder or killing the citizens. There may be a more sinister meaning to that lack.
Given my set up, this would in fact a brilliant move for the Red Hand, giving them a secret ally on Brindol's flank - and it suits with Ulwai's red-herring info about recruiting monster's from the Giant's Shield, too.
I haven't decided yet whether Trask is acting independently or has been suborned, but I give you all this development as a free subplot, should you care to use it.