[Omnirizon]

I don't think the crossbow or spell items replace the spells themselves, that's not the point.

The point is that it supplements spells with solid, low fatigue, and quickenable artillery. Shinuyama has a couple of great commanders just for holding these items and firing/zapping them from the backline. Additionally, they have the natural resources and paths to forge these items. Boots of Quickness, Staffs of Corrosion, Wands of Wildfire, Banefire Crossbows; all require gems and paths that Shin has naturally, and can thus get an economy started in consistently.