imperial distance units are related by 12. 12 inches in a foot. 12 (* 440) feet in a mile. 12 has more integer divisors than 10, so it is more likely that you end up with whole units when you apply simple ratios. it's not a big advantage in the age of digital calculators, but it arguably makes day-to-day calculations easier.
but to answer your question, I don't think imperial distance units have an advantage with halving. 1 m / 2 = 50 cm, and 50 cm / 2 = 25 cm. no less straightforward than 1 ft / 2 = 6 in, and 6 in / 2 = 3 in. either way we can't go further without creating a fraction. imperial distance has a clear advantage with thirds. 1 ft / 3 = 4 in, but 1 m / 3 is unrepresentable as a decimal number.
of course none of this applies to imperial volume units which are related by various powers of two. these are much easier to halve, but do not have the advantage with thirds.
Inches are typically divided in powers of two. So you don’t have to represent the 5 digitally when dividing (which you can’t in the binary system).
So, if the basic unit you’re designing with is inches, you can scale up easily and add a 3 with the base 12. Or divide using only 2 which helps the computer out
