Measurement is quite a dilemma. You can’t quite tell the drifts until you compare it with something.
For instance, you know 1cm is 1cm because youre referring to the ruler, which you assume is referring to the standard correctly.
So if u have a 1-meter ruler that measures 1km by swiveling it 1000 times, versus a 50-cm ruler that measures 1km by swiveling it 2000 times, how do u know which 1km measurement is accurate?
Well, first of all, both rulers need to be compared against a known, believable measurement agreed by all, which is the standard (be it SI, metrics, etc). Bring both rulers near the standard and check for any deviation.
Until that happens, there’s no point arguing if team 1-meter did the measuring 1km X many times and took the average, or team 50-cm used 3 checkers at stopping points to prevent parallax errors and so on.