That doesn't make their players more loyal.
Brisbane are a case in point.
For years they were the only team in Qld, and there was no salary cap (or it wasn't enforced properly). They were a SOO team, and therefore they won things. Players wanted to go there and win. They had the pick of the Qlders, and a few blues as well.
Now they have to compete with two other Qld teams, and the salary cap is enforced. They still have a slight advantage, as the history of success is a big drawcard. They are also a one-team town, though this year a team was brought in that aren't that far away. This means that players don't have many choices if they want to stay near home, and also that the fame/celebrity/endorsement opportunities are greater.
The loyalty of Brisbane players hasn't really been tested, but it will in the next few years, as the Titans establish themselves. In fact, already this year has shown that the Brisbane of old is no longer around. I think it's fair to say that they are losing players that they don't want to lose this year. Berrigan, Tate, even Petero left because of money when it all boils down to it.
Brisbane's players are no more loyal than any others.
Souths are another case in point. Two years ago no-one would go near them with a ten-foot pole. Now players are moving there. Why? Opportunity, money (or in this case fringe benefits), and the chance to win.