Sounds good in theory but convincing any of the juniors to go over to England for a year would be a massive task
I'm not 100% sure it would be that tough.
Say, for instance, that the Tigers didn't think TDS was ready to play 1st grade. But, they had to re-sign him because his contract was up, or let him go. Another club- say, the Titans, offer him the chance of 1st grade to leave. This is how clubs lose their juniors now.
Now, lets say same scenario- but the Tigers offer TDS based off his potential, an upgraded contract at the same value as say, the Titans. But instead of the offer of a chance at breaking into the 1st team, you offer him a year loan, at his full contract value, to play regular 1st team football, at an associated club in England. Whay young player would turn down exposure to 1st team football? Then he comes back, a year later, developed, just as Api pulls the pin. He steps into the 1st grade side, ready to roll. This should be seen as part of their development, not punishment. Not quite ready to play regular 1st grade, too good to be in KOE.
For mine, more than helping out a club in terms of it's 1st grade selections, this is how clubs like Penrith, Brisbane, Warriors etc- who develop a large amount of junior talent only to lose them elsewhere under the lure of '1st team football' (which really translates to "more cash to play")- can maintain, and even 'overpay' young players to remain in their system until the natural opening into the 1st team becomes available.
This COULD help to take away the buying power of clubs that put little into junior development & actively promote the nurturing of junior players, clubs & systems by all the NRL clubs.