Archery Bombard working fine for me. I just have to build or capture a stack of early ballista and catapults. It works like archery/siege bombard of old and reflects era weapon capabilities more realistically. I have not evaluated longbow men if they can archery bombard (Battle of Agincourt), but by that era, I am using other deadlier units.
The mystery just became clear. We never set a DCMBombRange for archer units. I'll take care of it.