Small lenders and affordable housing groups are not fans of the draft of housing-finance reform from Sen. Bob Corker, R-TN. Corker’s plan calls for having five or more guarantors to promote competition in the marketplace, but some worry about the big banks becoming the primary benefactors of this plan.With several private companies purchasing and securitizing mortgages, advocates of the 80-page draft said it would help end the duopoly of Fannie Mae and Freddie Mac. The proposal includes winding down the GSEs to establish the new guarantors of which none would be able to control more than 20 to 25 percent of the market.