I might be wrong, but I think you are misreading this. We need §6M for those contracts, but it does not take §6M from cap space. We already have 51 contracts, rookie contracts only replace some of them. For example, signing of 5th round pick takes nothing from cap space, since his cap hit is less than cap hit of 51th contract currently counted towards cap space. Rookies actually cost us about §1,6M together (mainly due to 1st round pick, who has cap hit of 2M, which is 1,2M more than contract it replaces).