Drawing the bow for reproducibility

When Robin the Hood draws his bow (Fig. 1), one can always be sure that his arrows will hit the target with 100% accuracy and only marginal deviation. But what if the bowman is Little John, would he hit the target equally well? He may pull the bow differently and have a slight, uncorrected astigmatism. Or let's think of Robin using the bow of the Sheriff of Nottingham (don't ask how he got his hands on it); would he still reproduce his initial high performance? How about Little John with the bow of the Sheriff? What if it's not even a bow but a crossbow? So far, I didn't yet even touch the issue of using different arrows handcrafted by different manufacturers or the quality of the interpretation of the results by the referees!