You let Kearnen have her way. Mortwake stops faffing once he has a bullet in him. The Furlbrows go down easily enough after that. So do the Defias in Moonbrook, though they seem to have some notice. Kearnen figures Mortwake was a liar in addition to being criminally insane and tipped them off. But no harm done, really. Your tank makes Moonbrook a bit too much like Southshore for her liking, but it gets everyone around as much vengeance as required.
At the end of the day, that's all you can really ask for.