I have read similar discussions to this one, as I’m sure you have, about making precision ammo on progressive and turret presses. The consensus in the articles and threads that I have read is, all being equal, turrets and progressives will never be as precise as SS presses simply because there must be some clearance (air gap) built in to allow rotation of the turret or the shell plate. If you eliminate that clearance, the turret or shell plate can’t be rotated, so you would in effect have a single stage press anyway.
I certainly agree with you that the “the right person” certainly matters when making precision ammo, but I think that even that person will make “better” ammo with a SS than with a progressive or a turret. Especially with a progressive that has so many operations happening at the same time that influence each other. That’s my story and I’m sticking to it.