[Saber Cherry]

Stone bird is great with Astral Weapon, and not great otherwise, as strength is not added. Lowering defense is not very useful because IIRC the misc-slot weapon is the last to strike. However it is indeed doubled with quickness.

If your SC is not casting Astral Weapon and Quickness, I suspect Bracers of Protection, Cat Charm, Missle Res. Amulet, Lucky Charm, (or for a living SC) Ring of Regen, Girdle of Might, or Amulet of Resilience would serve you better. If you have blood, a Soul Contract is also excellent for an SC and will keep them from ever retreating, even when grouped with other units.

Edit: Another consideration is repel. Both of those are length 6, I think, so they can be useful against (e.g.) spear units if your SC doesn't have any other long weapons. But repel is only very good versus low morale units like militia.

So... generally I avoid those, but with Astral Weapon the bird is always better and without the Trident is probably better in most cases.