It's isn't easy for co-heads of a firm to always stay on the same page. But it's rare that they contradict each other. Yet Co-Chief Investment Officers of PIMCO William Gross and Mohamed El-Erian appear to do just that if you compare two prescriptions that they recommend for the U.S. economy. At first, they may appear to agree, since they both want the government to do more. But the different type of stimulus each recommends conflicts. Let's start with Bill Gross. A few weeks ago, at the Future of Housing Finance summit at the Treasury, he recommended that the government use Fannie and Freddie to stimulate the economy by allowing refinancing for borrowers whose loans are backed by the entities at rates even below the already record lows.