I mean, they use Cannons and Bombs and other mechanical devices(like the snares on Steps of Faith), ostensibly made at the Skysteel Manufactory(likely at great cost, considering the size of some of these contraptions)to fight the Dragons.

So why would they logically shun the idea of mobile Soldiers carrying handheld Cannons, with mass producable ammo, capable of hitting AN AIRBORNE Dragon at likely a far greater range than an Archer and possibly knocking it out of the sky for the Knights and Dragoons to finish off?

Wouldn't one think that such a thing would be an advantage in the War against the Dragons?