Well the availability of talent is a lot better in football than baseball. Also, players don't last much past their rookie contracts in football, so even once they hit unrestricted free agency often times they'll already have their best years behind them. Really, just about any team can do what the Colts have done and blow their whole cap on about 3 key players (QB, pass rusher, and something else) and go bargain everywhere else. You can field a great football team that way.