Answer:
I think the question is incomplete
Unity is important for an effective functioning of a country and for prevention of conflicts: if there was no unity, people could not finish bigger projects that require cooperation with others.
Diversity is important for innovation and creativity: if we were all the same, little would change and sometimes change is for better.
<span>Bureaucracy! That is the main problem of the empire and mostly the republic. The republic fell because the size of the empire was to big, the events were moving rapidly and there was no time for bureaucracy, voting, debating and so on. When Rome became an empire it didn't of course change immediately</span>
