Like someone else said, this would be impractical because most teams put linebackers or tight ends on the line on punt teams because they're big enough and fast enough to cover the punts. The gunners at the end are usually defensive backs. The blocking backs are sometimes linebackers or fullbacks, although I did see someone using a smaller offensive guard back there in a bowl game. If you only have the number restriction for the center, then you as an official had better be ready to cover the punt returns that will be going back for touchdowns.