I'd avoid the AFL and let the Premiers fight the battles. Let the Home Nations and Ireland take 2038 - we take 2042. We offer 16 stadiums not including Perth, Victoria Park, MCG or Marvel but including an expanded MRS with Indonesia and NZ.
The premiers will complain about their states being ignored or short changed. The WA Premier can work with the two AFL clubs and ensure interstate trips and byes and maybe a couple of games at Bunbury and a small compensation package.
The Qld Premier can do similar and even use the Gold Coast venue while relinquishing Victoria Park to go with Lang Park. The MCG while it is ok for one-off marches it has been told it is too large (sight lines for a world cup) and the AFL own Marvel so forget that.
The NRL have plenty of suburban grounds to play on but may want to play the SOO at another time or utilise Adelaide Oval, the MCG and maybe Las Vegas.
So after the 2 premiers have a whinge we get Perth and Victoria Park and Melbourne stays with an expanded MRS. Only major new builds are an Adelaide and Canberra stadium - both tailored to 30000 with foundations ready for expansion with temp stands to meet minimum numbers and the expansion of the MRS.
By 2042 the first of our HSR is hopefully built and more of the Indonesia HSR is built.