The only mobs that should be using the special_abilities string to forcefully give them ranged attacks would be Kromrif Spearman (or any other throwing attack mob)
I know that ranged mob on P99 are using the values for ranged attacks in this string instead of the actual bow + 1 arrow mechanic because I killed this centaur foal (which did indeed shoot me with arrows) and he dropped a bow and no arrows.
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Here's a video of me massacring a bunch of centaur foals on live, and every single one drops a bow and a single arrow, no exceptions. It's obvious that ranged bow attacks are supposed to be tied to having a bow and an arrow in the inventory.