Should be having players make the Harm Move every single time anyone "harms" them regardless of how much actual harm they take? There is, I believe, an example in the book of a player making the Harm Move even when her armor negated all the damage, so thus far in my game, I've been having the players make it every single time they are hit by a weapon or fist or bullet, even if they don't actually suffer Harm. But last time it occurred to me that even if you're only adding 0 to the move, that's still a better than 50% chance of having something bad happen, which seems a bit harsh.
And what have more armor than the harm rating of the weapon? Should they make the harm move and subtract from the roll?