The best way they can look at funding grassroots sport is looking at how others do it.
I don't mean this to sound pompous or anything, but they should look at England. I grew up in the 80's and 90's and throughout that time (and into the 2000's too), England played their football a lot like Australia (both mens and womens) play now. Against weaker nations are very strong, against the best nations they struggle to control possession against a better skilled team, and therefore are always under pressure but try to attack on the break. Essentially this works at the early stages of tournaments, but at the pointy end, that quality and control of the football makes it very difficult to score, and on the other hand weight of numbers normally indicates you will concede. Growing up, we had countless last 16 and quarter final exits from tournamants, so the focus was put on St Georges Park. This was essentially a much larger centre of excellence where club teams could train, but all ages of England internationals could perform there. It was essentially set up to house the best of the best and have the highest quality training facilities and coaches in the same place.
Australia used to have something similar in the AIS (probably similar to what England had before St Georges Park which was called Lilleshall). It takes time, but it has an impact on quality and skill and I think we are seeing that now with both England mens and womens national teams being able to compete much better at the pointy ends of tournaments as they can control the ball and therefore dictate the pace of games much better.
I'm sure the FFA want to jump on the current elevated focus on their game, and this is the type of stuff they need to do, to engage more kids into high level training in a centralised training camp environment.