Arguably the star player in SL is being paid £200,000 (for a number) a season and is happy with that. However new rules come in that allow far less talented players to be paid more than their talent deserves and gets £150,000 (for a number). Mr Tomkins thinks he deserves more money and the next chance he gets he switches to RU.
Personally I don't think this argument stands up. Since its the club owners that set the wage I'd see it happening more like this:
Lets say we have 2 players, lets call them ST and PW. ST is one of the best players in the league and earns £200k (as per your argument). Player PR is a player getting to the end of his career and hasn't been hitting the highs for the last few seasons having been hit by injury, but is still rated as one of the better players in his position (not to mention a good goal kicker), and is on, say £125k (bit vague here because you didn't state what their original base salary was). A salary cap increase occurs and PR tries to negotiate a salary increase to £150k. From here we have two outcomes.
1) the club owner looks at the situation and knows that the chances are that all the players on the books are going to look for a pay rise. He does his calculations and negotiates a sustainable increase which he could, if they pushed, give out more or less universally to the players to keep the pay steps the same as they were before the cap and keeping all players happy.
2) the club owner gives in to PR's demands and gives him the £150k without thinking about the implications for the rest of the players (this is what we should call 'bad management'... could you really see Lenigan doing this?). Player ST looks at his team mates wage increase and realises he's now onlyl on £50k more, but he's twice the player PR is and deserves more muhahahahahaha, he goes to renegotiate but is told. His agent entertains offers from league and union clubs. Other league clubs, either newly taken over by very rich doctors, or who have been run more sustainable salary caps and just lost senior players offer £300k because he's worth it, union say "hrm to get this player we're going to have to pay £350k AT LEAST, previously that was only £250k, thats too much of a risk".
I can also envisage scenario
3) PR gets his pay rise to £150k, ST says "awww the old mans getting to top his pension up. Bless! I'm still on £50k more than him and I can renegotiate when he retires next year for even more.... muhahahaha"
Personally I think Lenigan is more likely to do option 1, although there are club owners in the league who probably aren't as good at running a business.