Stormcaller is pretty fine versus Animat and other foes sensitive to shock damage.
Other great weapons for ranger are which ones that proc stun: Borresaine, One-Eyed Molina's Gold-Fingered Spike-Flinger (also very fast if patched), Rod of Pale Shades (also decrease defense), Aedrin's Wrecker; not to mention the only ranged weapon with prone effect: Puitènte med Príncipi (also tow damege types).
These makes ranger great also in CC. With blunderbusses you can proc stun realiable with Driving Flight, Twinned Arrows and Stunning Shots. Also Golden Gaze is good in that and has a nice proc.
Fast ranged weapons is also cool: The Rain of Godagh Field, Wendgär, Forgiveness, Pretty Pretty's Rib (also Rending).
Twin Sting is awesome to proc Predator's Sense and has also a great spellchance.
Marking weapons is another wonderful thing in a party: St. Garam's Spark, Pliambo per Casitàs (also disorienting!), Cgadob's Hazel.
With ranger's high accuracy also Annihilation is and awesome enchantment: Dulcanale (also Rending), Sabra Marie.
Fulvano's Blunderbuss can make you a charme spammer and Silver Flash is insane with blind effect.
Sure I'm forgetting other good synergies, but we are plenty of weapons for rangers, while Rogue has less chance to stun, prone etc. with weapons, if they take them they remove a weapon for other people (think about barbs...), they can rely on usual sabres and Annihilation enchants and above all they must (not always, but often) go melee without a bodyguard (as AC is).
Early game rangers are also more effective with their accuracy form distance, rogue is too squishy and can't rely on many abilities, while ranger is good yet also with only autoattack.
I hope you can experiment and see