Euros and dollars don't have stupid orders of magnitude , you have either one euro/dollar or cents (in both cases 1/100)
Latin and Cyrillic , just different symbols , same as the euro/dollar thing , just different names , you don't add letters either.
German vs Norwegian , language , well ok this one might be _slightly_ comparable to the issue at hand , one has to be a little more rantional than the other.
Zed and Zee , again , just an aesthetic issue.
Inches vs centimeters 1 m = 100 cm , 1 Foot = 12 inches. Now quickly tell me how many inches does it take to span 892360213452 feet cause i can just add two zeros at the end to do the conversion in metric.
If one foot was some arbitrary scale of a meter and it would be equal to 10 inches i would have no problem with it and would've cheerfully agreed with your analogies , but it is not.