It`s quite simple, "MONEY".
The Wests Magpies don`t have a lot of money to pour into their juniors, other clubs such as the Roosters (Paea brothers etc) and Parramatta (Hayne, Inu etc) know this and do their best to poach any promising young Wests juniors. Any 14-15 year old who is offered a couple of grand to jump ship will jump at the opportunity, the Wests Magpies aren`t in a financial position to regularly do this, hence the reason the Wests Magpies need to keep a close eye on the situation.
Another to escape the net is Michael Greenfield who is now starting to show his potential despite playing in the under achieving Souths side.
On Gareth Ellis, I too am reserving my judgement, but my gut feeling is that he`ll be a hit in the NRL, I just hope it doesn`t mean we lose either Heighington or Te`o because of it ?