Choice of words being in question does not mean there were not good intentions. The OP sets the context for the level of detail in question. Referring to the premise as "overthinking" has the connotation of mocking the idea or the question, although may be making a useful point, if stated in respectful terms.
"Overthinking" seems like a way of saying "don't work at a level of detail greater than mine". Perfectionism may not make a practical difference but may provide satisfaction in thinking of ones work as high quality. It is personal in some regard. On the other hand, bringing a precision rifle mindset to handgun reloading may be a waste. Whatever. To me it is a matter of whether ammo looks right, spot checked under magnification, and fits in a cartridge gauge or in a chamber shorter than standard, lead bullet or otherwise. I know how to make that work. I refer to hand gun ammo.
It remains that if a COL changes from seating to finished round, something isn't exact in the crimp, although there could be very good ammo there regardless. Perhaps best to think of acceptable measurements as a working range. It can still be useful to understand what is happening in the process.
I only use an FCD for rounds culled from a gauge check and which do not provide any clues about what to fix. If still not gauging, I pull the bullets. I reduce the culling percentage by making sure my components are as uniform as possible. One particular culprit are lead bullets larger in diameter than expected. I do a lot more bullet sizing now, often finding a whole box .001 oversize and causing issues. Then suddenly everything is working.