Roman had Vic manufacture a hundred individual longbows.
Longbow archers were a ranged unit, serving a suppressive function.
They were not very effective against heavy armor units but could hold a significant advantage against less disciplined troops.
However, their training was exceedingly difficult, even for a professional army detached from all other duties, it took half a year of training to be considered qualified, and the logistical challenge was enormous.
Arrowheads and arrow feathers were the least of the concerns; the former were easily cast, and economies of scale meant that producing tens of thousands of iron arrowheads at once could meet their needs for several months.
There wasn't much difficulty producing arrow feathers either, as this land was abundant with birds.