Interesting topic. Looking forward to seeing lots of different opinions on this. Personally I see warbows back then as rifles today. Government issued in times of war, mass-produced and as normal during conflict as anything else but not personal or unique or made by the soldier.
Considering that the bowyers guilds kept their bow making methods a secret, and it was only passed through generations as compared to being shared with the community I think it's unlikely that everyone was making their own bows. I can see logic in the theory that perhaps some guys made their own from easy-to-find materials such as ash, holly, plum and hazel to have a bow to practice with but I would imagine that in most cases they were very simple affairs. Probably not particularly well finished or perfectly tillered as compared to the military-grade Italian, Portugese and Spanish yew bows that were made specially by the guilds and kept in storage for military use. These bows would probably then be handed out to soldiers in general. Looking at the bowyers' marks on the Mary Rose bows and the detailed tables in Weapons Of Warre, there are lots of recurring marks - bows can be grouped based on the marks. There are sets of chevrons (3, 5, 7 and so on) in fir tree patterns or crosses and these seem the most common. Perhaps the number of chevrons indicated the draw weight of the bow, and each soldier knowing his own draw weight would take a bow from the right chest or group safe in the knowledge that the bow would be within a certain tolerance of his particular draw weight.
There are bowyers' marks that are more unique - circles, crosses, intricate stamps etc - that might suggest personal bows or bows for higher-ranking archers or group commanders.
Whether there was a production line within the guilds is a really interesting question - we know there were horners who worked horn (and Mark Stretton's theory is that the young cow horn with it's natural cone hollow was prepared by the horners and then worked into a basic shape by the bowyer) but it's a fascinating thought that perhaps there were trained bowyers who prepared the stave - roughed out the stave blank into square stock and established tapers - and a second bowyer rounding corners and tillering (as Jaro said, once the tapers are established on a Mary Rose style bow, providing it's been done carefully and accurately then tillering only takes 40mins or less)
