The whole player agent arrangement in NRL is a farce.
In particular regarding conflict of interest, which necessarily arises whenever an agent has multiple players at one club or is trying to get a player into a club where the agent already has other clients. The salary cap and limit of a top 30 squad means if one gets a spot then another can't, if one gets more money there is less for the others, etc etc.
As for enforceability of ethical standards and compliance with NRL rules - yeah right, if Manly goes to dob in Tartak then Tarkak might use his influence for revenge when we try to retain some our best young talent.
Not sure how agents work in the big overseas sports but I suspect they are much more tightly regulated.