FLOWERY BRANCH — The mandate came from the top of the Atlanta Falcons' chain of command when the offseason began. Owner Arthur Blank, echoing what coach Mike Smith said the day after Atlanta wrapped up a 4-12 record, demanded that the team get stronger and stouter on both sides of the line of scrimmage. For the defensive line, that meant acting quickly in free agency to sign 345-pound nose tackle Paul Soliai and 296-pound end Tyson Jackson to fit a new 3-4 scheme.