He would talk to the Ferals to try and see if there is a quest in the North - that does seem likely. But at the same time, these two seemed out of information last time. And without more information there really isn't any place to go. Just "North?"
There is another adventure hook here in town discovered while walking around. Daxos would share that detail with the group once he gets whatever information there is to be gotten from the ferals. For lack of a better plan, I'd say we talk to the ferals and then follow that lead.
I, like Impulse, as a player see no reason to kill them either, but as Clary.. She was raised by a wolf, before that she knew only hardship and cruelty from her human family. She would go to the harshest punishment for them for what they've done to the people of Pike- even if Pike was at fault, she would still lay blame to the ferals.
That being said, that info about Clary being raised by Silinrul is for PLAYERS only. The Character's don't know much about her yet.
If the decision however as a collective whole was to keep the Feral's alive - Clary would listen. She'd be confused and angry as to why they were being spared when they infact didn't spare the people of Pike at all. But she would go with the collective whole of the group.