Okay, my blind guess was off. Maybe I'll talk about the "running fights" problem in another thread.
I haven't seen a problem with the PCs being hard to threaten (quite the opposite) so I'm at a bit of a loss. You said you're having trouble knowing how to press the attack in the fiction, and what you're allowed to do as GM. Maybe say more about that? To me, it seems the same as in AW.
Do you do the thing where you scale the challenge of an NPC (or monster, in this case) by how their fictional attributes impact which moves the PCs make make (and how they make them) when they fight?
Like, the simplest example: when they fight a dragon with teeth as long as a sword and a great lashing tail, and foul breath that can stagger a horse, and the Fighter with the longsword says, "I hack and slash it!" I say, okay... uh... how? If he says, "With my sword!" then I laugh and laugh until he comes up with something remotely plausible.
Or if he glares and says, "No, seriously, I stab it." Then I'm like, "Okay! You rush closer to get into reach, and the dragon's tail lashes out, smashing the stone wall next to you to pebbles and arcing back toward your legs. What do you do?" That's, like, part one of getting close enough to a fire-breathing giant monster to stab it. Wish him luck with parts 2 and 3.
See how that makes the dragon a major challenge to the guy with the sword? Maybe you already do that -- it's a thing I do in AW, too. I'm just trying to get a gauge on how different our approaches are.
@Ludanto: Yeah, that's what I meant. Well, that, and also when 2 of the goblins attack the fighter, while the other 4 rush around in the shadows and try to stab the wizard in the back.