I think you're right, although they were making hundreds of thousands of bows in a fairly short space of time and the bows had to be good enough to pass muster and be war-worthy. You wouldn't send troops into the Middle East today with poor quality firearms, and they wouldn't have issued poor quality warbows back then. While we can take our time and spend a week tillering one bow to a perfect draw weight, fitting beautiful grips and snake-skin accents and sanding it to look like glass and carefully shaping horn nocks and so on, I just can't see that back then. Mass produced quickly but to a very high standard is my guess.
Whether this means highly skilled bowyers working in the same way we do, or whether there were methods used such as fast reduction of staves by one bowyer and rounding/tillering by another or a combination of the two we'll probably never know.
One thing that I'd really love to know is the draw-weight quandary. Did they know draw weights, or was it all just base dimensions and the outcome was the outcome depending on the timber? We'll never know that either. Personally I find it slightly unlikely that the soldiers were trusting their lives to a bow with an unknown draw weight, but without accurate scales and methods of measuring the bows, I can't see how they would have been able to know. Fascinating, either way, and all the more reason these weapons and their history are so exciting!