NNSW npl has changed to a 18s 20s, 1st grade from a 19s, 23s, 1st grade model just for the information.

Don't really have an opinion about which is better but it has been an interesting thread to read. I have a question though, Is it the federations driving the removal of a "second grade" to promote youth development or was it driven by the clubs to cut the costs of fielding two teams of seniors when player payments were rising? Particularly since, at least when I was playing back in the day, the first grade and the reserve grade had their own squad of fresh reserves for match day. Better for clubs financially to have one squad and offer contracts to local league first graders for injury replacements if needed.

Why wouldn't you? If it's the best practise, easier for scouting for youth tournament, etc.

FFA Regulations

Is there no agreed model for development ? 

Some club's don't pay 20's though

And apparently 19's won't be apart of seniors next year only 23's & firsts

Also, the 20s NPL allows, I think its 3, overage players. I know that with the Riverina Rhinos for example (where the reserve grade is effectively the local association competition), use the 20s as a de facto reserve grade. I do know our first grade has a lot of players under 20, who dont play NPL20 (probably the main reason why our 20s side is rock bottom after 4 games)

This is where, as i mentioned in another thread, I thought there was national standards with the NPL. NPL23s would be good instead of 20s though.