Many MENA countries are heavily influenced by Islam just as many Latin American countries are heavily influenced by Christianity. Do you think this is good, bad, or neither? Why?

Many groupings of human populations are based on similarities in language and religion. For example, we refer to Latin America as a grouping of similar people because Spanish and Catholicism are predominant. Based on your understanding of individual difference, how useful are these kinds of groupings? For example, if someone from a European country were taught that U$.$S$.$ Americans are all fairly similar because they speak English and practice Christianity, how useful would that be for that person doing business in the U$.$S$.?$