In universe, if they are hand made by the respective bowman, even if they casually look identical forensic examination would reveal them not to be.
Production wise, yeah, one supplier is likely. That's just a reality of making the show though and should have no bearing on the internal logic unless specifically addressed as such in universe.
Production wise, yeah, one supplier is likely. That's just a reality of making the show though and should have no bearing on the internal logic unless specifically addressed as such in universe.