Manufactured Weapons

As noted in Items, most creatures have less treasure than PCs, so those that rely on manufactured weapons are significantly weaker if you don't adjust the weapons' damage to compensate. The method for determining Strike damage abstracts the sources of damage, so you don't have to worry about adjusting the weapon's damage. If you do decide to calculate the weapon's damage, give your creature weapon specialization or greater weapon specialization much earlier than a PC would get it. You might also need to add sneak attack or similar abilities to make the creature deal more damage.

On the flip side, you might want to use a one-off creature as a source of a particularly high-level piece of treasure, such as a magic weapon. In these cases, you might want to make the attack bonus higher for the potency rune or the damage higher for a potent striking rune so the PCs feel the weapon's effect before they obtain it. This will make the treasure feel more powerful since they've already been on the receiving end.