The wisps and clickings of crossbow fire hissed through the air. The Dres in loose formation and out of sight would provide poor targets but precautions were taken. Keeping with the Velothian Tradition the Dres maintained an avid study of conjuration and dealings with Daedra. Momentary cuirasses and tower shields were provided by the otherworld via the Arcane ability of each rider. Arvas felt the clinks and bangs of the bolts striking the Daedric shield. His horse neyed loudly as it was struck in the side, a glancing blow at an angle and slowed down by the composite lammelar armor made for protecting against missiles. Though the Dres had to cease their barrage the crossbow bolts were in large part ineffective landing harmlessly on the ground, striking the bound armor. An unlucky few recieved their end while others had been wounded. Arvas considered the trade off as acceptable and continued.
Thats not how it would work out.
armed with their trump card: the arbalest. The arbalest has a maximum force of 5,000 pounds force, enough to rip through ebony, adamant or even Daedric armour.
Taken from the Crownsworn profile. They wouldn't be bouncing off the Bound shields home diggitty dog. And their max range was never 500 feet, it was 500 meters. That would shred your peeps, not bounce off harmlessly on the ground, or just hurt your a horse a bit, with respect to its armor.
Bound items, they can't be dropped. I mean we can keep the arrows that have never been mentioned before, and just become better as time passes, but these two things were the main issue, especially the Arbalest part.
Also, volley fire shouldn't be an issue, unless you mean firing in the air so bolts can "rain down" on you, which is not what their doing.
Their aiming at you, considering the force and range, it shouldn't be an issue on their side at all.