the french at the time, who faced the prussians, thought it was their speed of movement rather than their firepower which mattered – even going so far as to comment that while they reloaded very quickly, they hardly hit anyhing more than they would have had they been at the same speed as everyone else their aim was so poor.
when you look at fredericks battles, expecially in the 7YW, what he does is let the enemy fix their position, and then march right around that position to the point he intended on attacking – often on the corner or even a point in the rear.
By marching far faster and more determinedly than the semi fixed opponents, he was then able to avoid most of the defending army, and concentrate his best troops at the point of attack.
Local superiority then determined who broke through there, rather than any inherent troop superiority.
and the reaction was to develop a method of defense based on digging in and, from the austrians in particular, a method of attack based on multiple converging points of attack (e.g. hochstadt) which prevented Fred from taking troops to the threatened area to reenforce it for – again – local superiority.
the recurring theme of this local superority at the point of attack emphasises to me that his men were not that much better at fighting, as he never seemed to attempt simple face to face even numbers attacks if he could at all avoid it, which is what you would expect if his men were that much better at shooting.
the contrast with 1805-06 Napoleon is striking, where he would attempt strategic superiority, but make tactical attacks head on with a pretty even ratio of numbers while using the superior numbers he had accrued to try to flank and encircle for a total army destruction.
Note that the severity of Fred's drill was all about keeping them in the ranks under fire and marching fast and in formation.
rapid reloading was an intimidation, I think – along with the much more rapid manoever – and his reputation.
plus he had the best charging cavalry by the 7YW, which would win the cavalry fight and then pursue for the dramatic victories.
of course, the notion that the prussians could out shoot everyone is so ingrained now, attempting to suggest that the evidence for it is not as strong as it needs to be to be true – and largely based on 'instruction' taken from Prussians after the wars (when fred would laugh at them for learining the wrong things) is a bit pointless.
we want to see prussians as firepower dominant, for some reason.