My own life interests and experiences fit your Polymath model quite well, but I've never seen the term "polymath" before.
The American educational system stresses foundational proficiency while affording nearly limitless opportunities to explore beyond apparent academic boundaries. American multicultures allow one to access the diversity of world belief systems. It's worked for me. Every Friday, I meet with my two business partners--one an Indian Hindu, and the other an Islamic Pakistani.
Why did you reject "Renaissance man"?