I knew of a team playing Under 16's many moons ago (they are all in their mid 20's now) that had 33 players on their books. Like Guiness Draught, they didn't travel well, and at one game they only had 12 players show up due to injuries, no shows, work, Thredbo, CBF etc. They started the game playing 12 vs 15 (and bench). The end result was that they had to forfeit the game when leading 38-5 with their 12 players.
Unfortunately one of their players got injured just after half time and could not play anymore. They were then unable to field the necessary 12 players to make it a game (as per rules). The opposition manager claimed the 28 - 0 forfeit at that point. A little petty, but the rules allow for that.
Some teams can make it in the 16's with 25 kids "on the books", but it is a close run thing each week and you need to have lots of CCC, and CHS kids. This is something that the East, North shore and Inner West are lacking in.
The reality is that teams in the North, East and Inner West need about 30-35 on their books to remain viable for all 14 rounds, plus rep duties, plus school games. Not many village clubs can muster those numbers at U16 level.