The reason WT don't have a good system though, is because of the lack of job security at the club over the years. A new coach comes in, and he starts all over again. Poor recruiting over the years led to a decent proportion of the top 30/dev were SG Ball players.
A good system is the Roosters. Their young halves unit is Sam Walker (22), Hugo Savala (23), Sandon Smith (22), Jake Elliott (20), and Toby Rodwell (19). Smith got his opportunity with Walker's ACL injury. Savala got his with Townsend's poor form.
Smith, Savala, Elliott, and Rodwell progressed or still are progressing very well in the lower grades. Rodwell steered their u19s to the SG Ball title with Boyd Cordner as coach. It's a system with outstanding junior recruiting, and player and coach development. Largely because they have built it up with a head coach who has been there for over a decade and invests in it.
Galvin, TDS, Mason, Luke and Kit Laulilii, Latu Fainu, Miller, Feledy, Matamua, etc. All these kids were exposed to NRL way to soon, because the club recruited poorly. Some of them have played more NRL in their young careers than reserve grade, flegg, or Sg Ball. That just shouldn't happen.