Kitsunin, I don't usually track harm to npcs, gangs and vehicles as cumulative, no, so in my games shooting off two pinkies probably wouldn't constitute 2-harm. I view the harm clocks for npcs, gangs and vehicles as cues and descriptors for the MC, and so they are very different from PC's harm clocks, which tracks a cinematic style of harm (the shotgun blast grazed you, but the knife coming after went right into your gut).
That said, if you have doghead on the ground and you're just punching and punching and punching, then sure, I'll let the harm accumulate