Harrison Barnes just put $25 million into a bank in Paton, Iowa. Population 220. Run the capital math and the feel-good story gets stranger. Regulators let banks hold roughly ten dollars in assets for every dollar of equity. $25M in capital can support close to $250M in assets, most of it deposits the FDIC already insures. What Barnes actually bought is a charter, a document that's gotten brutally hard to obtain since 2008. The FDIC used to approve over 100 new bank charters a year before…