Back in the bad old days at the end of a season all the good players would line up and join the club who would pay them the most.
The Australian (22 jan 2008 p16 Ray Gatt) ran an argument that CCM with salary cap pressures and success behind them, together with many players coming off contract would have their better than average players targeted by other clubs. This is the way the salary cap is supposed to work. Spread the good players around and keep it all even as poorly performing clubs would pay more for better than average players than top performing ones. This outcome would be good.
However, there is the issue of player ambition, opportunities to be in a team that will draw the attention of the Socceroos, as well as opportunities to play in the Asian Champions league and to get watched by international talent scouts. Also, for strikers better performing clubs mean getting better final balls and more opportunities for goals. These factors mean that better than average players may be prepared to accept less to go to big clubs. And other clubs that can already offer an Asian Champions league spot can also draw talent away from lessor performing clubs.
Sometimes the lessor performing clubs must pay more for players of only average quality because of perceived lifestyle costs and remoteness from family. They tend to be filled with players either at the very end or the very beginning of their careers.