Penrith are not cheating the Salary Cap. They are playing a smart long-game.
They have access to the breadbasket beyond the Blue Mtns (Lithgow > Griffith East-West: Armidale to Wagga Nth-South - HUGE intake). The personal conditioning developed to 'Play for the Panthers' in those regions provides a very large source of prospective talent. Juniors: Tick.
Helps that they are doing well in the comp nowadays, almost entrenches their privilege as a destination-club. Play with Cleary, Martin, To'o, Edwards, Fisher-H, Leota, Luai, Crichton.... Desirable career-enhancing location: Tick
Combine that with a leagues club with majority ownership, that has the largest amount of Poker Machines in the southern-hemisphere-per-square-meter - bascially milking their fans for a funding source of unparallelled riches which can support aspirations of greatness - and they have the Royal Flush of income. Funding: Tick.
Then they got in Gould, when he still had his faculties, to guide club strategy: (Arugably) Tick...
Penrith have played their hand as well as they could. When up against the might of Newscorp-majority-holder Brisbane, or League-defining-AFL-combating-Storm; Impeccably-managed-and-Politis-fueled-Rooters, or Star-power-Rusty-knobbing-Souths, they have found a way to flourish and out-do them all. Ku. Dos.
Regardless of the means, you have to respect the ends.
We used to have that Big-Mac special sauce at our club, but it has since turned into a simple recipie of leaving Mayonnaise in the sun for the epectation of the same results of bygone eras in the modern game - by the Penns/Execs of today. (Yes, that is a Simpsons reference....Owning it)