Why did alexander make such a strong effort to blend the cultures of his empire?

Alexander knew that if he just forced the Hellenic culture on the nations and people he conquered, there would be mass resentment, and uprisings. He blended cultures to prevent that, and really, it worked.

The second , larger puritan colony of massachusetts bay was conceived as a "city upon a hill". but it also struggled with internal turmoil like the salem witch trials and external conflicts like king philip's (metacom's) war.