If the party chooses to disarm a group of kobolds in a successful manoeuvre, will all kobolds lose their slings? Or only one of them?
The rules only seem to use the example of a single monster: “For monsters, you may render one of it’s weapons useless for the remainder of the fight.”
There’s an exception to this rule with the elf ranger’s 5th level Master ability (Dagger) — that allows you to disarm multiple opponents. Because I this, I sometimes allow a second (or theoretically third) disarm if you can put up that many successes. MoS 6 is hard to come by, MoS 9 is pretty much unheard of. However, this is all dependent on the effect making some kind of sense in the scene.
Thanks, Jared and Lincoln!