Back when I was in my state high school about 5-10 years ago, one of the PE teachers was from Sydney and was big on his Rugby League, so he got a few of the students, like me, who played a lot of different sports and would be open to the idea of learning/playing RL, to convince a few mates to put together a school RL team. We played in a single tournament of which the winner, straight away, went and played the winner of equivalent competitions in SA/WA etc., who, the winner, in turn, would enter the NSW/Qld schools competition part-way through. Googling around, it turns out that it's this competition, I think.
AFL development have done a great job. RL development are useless
Back when I was at school (a long time before you - mid 1980's) my high school in Newcastle put together an Aussie Rules team for the state knock out. Only 3 of us had played before, none of the rest of the team had ever seen a game live, and I was the coach - our PE teacher was officially the coach but he let me run things. In one game I had to umpire half the game, as did a player from the other team because there were no umpires available and neither schools "coach" knew the rules.
Somehow we won through the first 3 rounds before being knocked out.
Compare that with where the game is now..