I think that whole story arc is about Stacia.
In Fallen Stars there was a conversation between Ned Granger, the North Carolina alpha, and Kral Vrana the Carpathian alpha, about Stacia, how she changes and the purity of her strain and what her bloodline would mean “for our people”.
Then in Rogues, she says that she the assistant to the Alphas of the New England and Mid Atlantic region.
Paraphrasing the conversation went something like,
Declan – That’s new isn’t it?
Stacia – There was some consolidation.
Declan -Some dumbass alpha from a smaller pack challenged Brock and lost.
North Carolina is in the Mid Atlantic region.
I think that challenge was an attempt to take over the NY pack so they could get control of Stacia. Ned Granger, the only mid Atlantic aLpha we know of, struck me as the direct sort which would just walk up and challenge you for what he wants.
Kral Vrana on the other hand struck me as the kind of guy to use pawns and come at his opponents widdershins. Why risk losing his pack in a confrontation when he can work behind the scenes to isolate her from the pack. Then he only has to deal with her non were mate, which if Declan was a normal male witch would be easy to do.