Is Calvinism Manichean?

A popular Arminian trope is to say that Calvinism is based on Augustinian theology, and Augustinian theology is colored by Augustine's residual Manichaeism. 

i) It's absurd to claim that all Calvinists are getting their theology mediated by Augustine. Even if Augustine was a major stimulus for Calvin, it doesn't follow that all or most Calvinists arrive at their position by the same route. You can be a Calvinist without reading a page by Calvin or Augustine. 

The Reformed tradition points people to Biblical prooftexts for Calvinism. So many (most?) Calvinists are getting their theology from the prooftexts. They find the prooftexts convincing. While an Arminian will say they misinterpret Scripture, the point is that their frame of reference isn't Augustine or Calvin but Scripture. 

To take a comparison, I can use a map to drive to a national park. And I can use the map to find the trails, and the scenic destinations. But once I'm there, I can see it for myself. What I believe about the park no longer relies on the map. 

Likewise, suppose I'm a park ranger, and my kids were born in a cabin for park rangers. What they know about the park isn't dependent on the route I took to become a park ranger and be assigned to that national park. Even though that's where the journey began for me, they begin at a different point. 

2. In addition, the genetic fallacy cuts both ways. We could just as well say that indeterminism is a pagan idea, going back to the role of luck, randomness, and chance in Greek philosophers like Aristotle and Epicurus. Therefore, freewill theism has a heathen pedigree.