You really ought to try a Wilson before you assume the tolerance stackup is worse than (or even similar to) the slop I have seen in my Lee gauges, lock-stud, cutter and let's not forget, the flash hole in the case itself. I have both trimmers; the Wilson wins hands down in the accuracy department.
Press fit into one end of the Lee gauge, you have a pin that rides loosely in whatever kind of flash hole your case happens to have. On the other end, you have a slotted (!) threaded stud that screws into the face of the cutter. Have you ever looked at the runout on a Lee gauge installed on the cutter? I can SEE it wobble on some of mine!
The Wilson's threaded stop block, case holders, and cutter bearing are all machined from ground round stock. All three ride on two thinner, ground round rods laying in parallel V-grooves machined into the base. There are no threaded pieces that involve centering/aligning the case to the cutter, only setting the overall length, and clamping the stop block and cutter bearing into the "ways". The Wilson trimmer is a simple design that is easily manufactured very accurately.
Andy