Your counterexample is not even close to being accurate. Italy and Switzerland have much more in common than China and Japan. Italian is even one of the official languages of Switzerland. Switzerland and Italy are both essentially federations of distinct provinces. Both are recognizably Western European. China and Japan are worlds apart, as are China and India.
My main point was that there's plenty of reasons for China and Japan to be different, especially when it comes to driving norms. Are you surprised as the other poster was about these differences between China and Japan?
And going back to the original intent: would you say driving in Zurich and driving in Naples are two distinct experiences?
