Since Jamal Williams is out for the season, should the San Diego Chargers move to a 4-3 defense?

To be able to run a 3-4 defense successfully you need a big nose tackle to clog up the middle. All 3-4 defenses in the NFL has that big body in the middle. Pats have Vince Wilfork, Steelers have Casey Hampton, and the Ravens have Haloti Ngata. The Chargers had Jamal Williams up until he went down for the season with a tricep injury. Since the injury the Chargers have tried to put Alfonso Boone and a rookie in Nwagbuo Ogemdi which have been utter failures. Would it be advisable for the chargers to switch to a 4-3 switching shaun phillips, shawne merriman, and larry english as defensive ends instead of outside linebackers. Especially since their defensive coordinator, Ron Rivera expertly ran the 4-3 when he helped lead the chicago bears to the superbowl a few years ago.