A group of investors affiliated with Franklin Templeton Investments that sued Fannie Mae in January has also sued an insurer, Radian Group, over its role in the GSE’s nearly $11 billion accounting and managerial scandal. According to the investors’ recently amended complaint, an unnamed subsidiary of Radian Group sold at least one “finite insurance” policy to Fannie Mae for a $35 million premium, which, as discussed in Fannie’s Form 12b-25 filing with the Securities and…