I don't think anything will ever workout just right for everyone to tell you the truth, in any kind of government.
Yep. So long as people disagree about moral/political issues, which is going to happen, one type of government for everyone cannot possibly be efficient at all, ever.
I'd advocate a re-distributing of "countries" based on political beliefs (people of similar belief systems could "live" where their governmental beliefs were upheld), but that would be a supreme logistical nightmare and totally impractical.