I will offer my 2 cents as a 7700 user for many years (have used my current set for 20 years). I have no issue getting the bearing adjustment done properly (all it takes is two cone wrenches and a little bit of patience) and I have overhauled these hubs most years I have owned them, so they have seen their share of bearing changes and adjustments. A few things I would check if I was the OP:

- Check the axle to see if it is straight. Uncommon for it to be bent with a cassette hub, but if it is it would cause some issues with getting the bearing adjustment just right. You can roll the axle on a flat surface with the DS cones hanging off the edge to see if it rolls true.

- Check the freehub to see if the "crunchiness" is coming from there due to seal drag. While well-sealed, the seal on the back of the freehub body can "catch" a bit on the hub mating surface, especially if there's dirt or grime back there. It's not a big job to remove the body from the hub (10mm hex key and a cheater bar). I use a Morningstar Freehub Buddy to lube my freehub, and do notice that there can be a bit of seal drag when it is reinstalled (usually gone after the first ride post-overhaul). This drag can be felt as a catch when the wheel is spinning, and the DS bearing cup is part of the freehub body, not the hub. Perhaps the OP needs to remove the freehub body and a) make sure the rear seal is properly seated, and b) ensure there is no dirt or grit embedded in the seal.

Good luck tracking down what is causing this. And to answer a previous question, 9 balls per side.