Lets say a given bow has an accuracy rating of 91, that doesn't mean at 1 wpf its 91% accurate, it means that as you get closer to the ideal wpf for that bow you near that accuracy rating (the smallest the reticules will ever get). The weaker the bow/xbow the less wpf is needed to reach that (but also the accuracy rating is lower). So given a fixed level cap and a soft cap on wpf because of the rapidly escalating price for each wpf point, the highest level bows (not xbows as much since for some odd reason you can use a siege xbow with 15 strength, but need 18 strength for longbow/warbow, which means you can go more agility and reach the higher possible wpf from 15/24 or 15/27 if need be) are the most inaccurate. Even given the exact same build of say 18/21 with all wpf points into agility and weaponmaster, the khergit and strong bow shoot more accurately at long distances than the longbow which is supposedly designed for long ranges, because they reach their maximum accuracy at lower wpf (though i don't think most people ever get to ideal accuracy, the lower the requirement the clsoer you geta dn the more accurate it becomes). Yes the shoot speed is slightly lower, which you must compensate for, but the arrow will shoot straighter (but more arc from less shoot speed) and is less likely to go errantly wide with long shots which is very common with longbows.
So essentially the bows/xbows most designed for long ranges with higher shoot speed are also the most inaccurate at those ranges (unless of course you use the glitch of shooting just before the reticules reach their smallest size and releasing (so no shots tracking opponents) and it will shoot dead on straight everytime, which is much easier with siege/heavy xbow or if you have low wpf, the longbow. So the system favors glitching to get accuracy and those who use it legitimately are punished with randomized shots.