How valuable an aid homogeneity is in forming a balanced political union

Balance is important in many things, it seems to be an art as well as a science. When the founders of the United States worked toward a balance of freedom and order, etc. it involved many elements that they hoped would form an integration, harmony, counterbalances, proportion, etc.  

Defining human nature had to somehow synchronize with defining social laws. A view that human nature was mainly individualist or mainly group-centered, equal or unequal, etc. would affect the outcome and the balance. Did it call for more government control or less government control? And how to handle the differing definitions and opinions of these things?  

We can see how valuable an aid homogeneity is in forming a balanced political union. The cultural, social, biological, ethnic and other similarities within a group affect the balancing of freedom and order, social laws and cultural mores; how much more difficult it is to balance heterogeneity and dissimilarities.  

I argue that heterogeneity and multiculturalism within the same living space make social balance virtually impossible, because real human nature is universally kin-centered, hierarchical, ethnocentric, even xenophobic, among other conservative things, with group-selection as the primary unit of successful selection. These things are best balanced in real ethnostates. The balance that the founders of the United States worked toward, the freedom and order they sought, worked as long as the United States was culturally, socially, biologically, and ethnically homogeneous, Euro-American, and naturally became unbalanced when we were not.  

When real kin and ethnic-group-centered human nature is allowed to be what it is, it naturally leads to regionalism, localism, ethnostates, and finally, if we are wise, an ethnopluralism of ethnostates. In the U. S. this could be accomplished by adapting the U.S. constitutional separation of powers and states to an ethnopluralism of ethnostates. All elements of the changed demographics in America could then be what they naturally are in ethnostates, protected from marauding imperialists, supremacists, and global money grubbers, by a light federalism.