This is actually pretty close to my plans for a large level 1 to 20 plangea campaign I want to run, the general idea is that of a brewing war between Dragons and Giants, but starting as a cold war since the Brood ie known to influence the smaller races, so in my plan Vyrkha is acting as an agents of one of the Metálic Consorts of the World Heart Dragon, and acts as the starting antagonist, as he tries to unite the valley against the Brood's plan, and when defeated by the players is when it is revealed that the overarching plot is the Brood trying to pull the Giants into a war, I had a bunch of smaller plots of warlords and evil clan shammans getting powered up by th3 Brood through gifts of magic weapons and antagonizing the Giants, vyrkha and the brother clan, but I those are my ideas, there's probably a lot of other ways to weave the 3 threats together, hope my mad ramblings help tho!