You forgot to mention the extra 20 million pa the nrl will get from sky nz on top of Australian broadcasters paying for the 9th gameYou hit the nail on the head there - The "let's plunder the junior talent" and "let's use NZ 2 to help fill that pesky early Friday timeslot" are the drivers for NZ 2 to get that 18th spot - and the fact that there are bigger markets sitting around untapped (Perth, Adelaide) doesn't matter in that reckoning.. even though Perth is ramping up it's local league scene year-by-year, and is producing home-grown talent.
no Australian broadcaster will be paying extra for a Perth or Adelaide nrl team
its pretty smart the nrl is getting sky to pay for the cost of the new team then they can profit from the 9th game via Australian tv and share those spoils with all clubs