Theoretically the two caps are the same but in reality they are not.
Leagues caps main purpose is to stop clubs from going bust by spending too much. Sure that will theoretically create a level playing field and to a degree it has. Though in the case of ourselves and say Salford just being able to reach the cap is bit a dream.
The pickings are slim in RL and frankly there is no need for any club to flout the rules like Saracens did to gain an advantage, so the transgressions and fines will always be small.
RU in the UK is different, it’s awash with money and talented players are available from all over the world including RL. The temptations are huge and the clubs are financially strong enough to take risks and pay the price. There is no talk of Saracens folding, imagine a League club surviving that, look at the fall of the Bulls, not a salary cap issue but similar.
RL can’t allow a Saracens full stop, even our idiots can see that, so the cap is enforced and it seems to work. We can’t afford a second Bradford, we’ve barely survived that one! Sadly RU is now so strong it can afford the loss of a top club and thus punish as it sees fit. Must be a nice place to be.