There are two problems with the cap for a club like alright firstly to sign players of the calibre of Hansen, Stewert etc you have to pay over the odds, they don't leave clubs like Catalan and Wigan (via. Salford) for the glory so to entice them to your club, we had it for years at Hull and now finally we can offer something more than money, it will take a few years to get to that level.
The 2nd reason is youth, yesterday we had 6 players missing, this meant our bench have 3 young kids playing (all on low salary) whilst you had 7 or so out but still had an experienced bench, you have too many experienced squad players, if you a youth/reserve team you can replace some of your squad players like Green with younger cheaper players allowing you to sign better quality players for your 17, again this will take years and patience.