It's almost like nothing in society is left to one mans discretion. I mean CEO of major companies don't have discretionary powers. Police officers don't have discretionary powers. Judges don't have discretionary powers.
What you don't understand is that discretion needs to happen because things aren't black and white. But with that discretion is responsibility for which the CEO will ultimately answer to the ARLC.
I think you have inadvertently gotten to the heart of the matter.
Ok I'm boring Timmah with my criticism of Greenberg. Im boring myself TBH but Greenberg is almost daily displaying his incompetence.
What I think you have raised in your post (whether you understand it or not) is that by being INCREDIBLY reactionary and all about bluff and bluster and how he and the NRL LOOKS, Greenberg has made himself less answerable to the ARLC than he is answerable to the media. He is being driven by the Media agenda and reacting to the media agenda rather than leading on principle and good decisions.
I understand that it is a bad look if DeBelin plays, Walker or Chee Kam for that matter, and it is not straight forward, but what is the over-riding principle? DeBelin, Walker and Chee Kam are innocent as they stand today. The right decision would have been to simply say "Player X has the right to presumed innocence and to have his day in court". It is not the NRL's place to step into this. Now it could be in the club or the players interest to stand down, but that is their decision and that is where the grey between the media publicity or public perception of DeBelin vs Chee Kam comes into play. Do you really think anyone is going to sledge Chee Kam?
By stepping into a realm where they really have no place, the NRL has opened itself up to legal and financial risks. There is no way DeBelin was going to play, Dragons have already shown their hand, but now you can bet your house that if he is not found guilty there will be a massive case against the NRL. So you have to ask why they have done this. Why have the NRL done this rather then leave the player to have his day in court? Because Greenberg REACTS to the media agenda rather than having the balls to set his own.
TLDR
Discretion doesnt need to happen at all, you leave it to the courts to do their job as the NRL has done for years. That would take leadership that doesnt bend to the medias will.