When looking at the leadership of any big bank from an investing perspective, the CEO often gets most of the focus while the board of directors can sometimes be overlooked. After the financial crisis, Bank of America (BAC 0.59%) had several experts from highly regulated industries appointed to its board of directors. Now that several of those experts are leaving, Fool financials analyst David Hanson highlights one trend he sees as worrying in the relationship between Bank of America CEO Brian Moynihan and several of the new board members coming in to replace those on the way out. Will these new board members have the banking savvy to challenge Moynihan and keep him in check or are they just yes men?