The talent is not the question, it's the financial viability. It's not worth having a great NBL if teams can't stand on their feet.
The AFL has done well because it has the back room financials all sorted. they are the benchmark in Aussie sport.
The talent is always there for as many teams as the NBL wants. At the moment the AFL soaks up all the Aussie talent for tall athletic player as it has the cash to splash around. One of my mate's brothers was on the Crows list but never played a game. He was drafted as an injury cover for one of their star players and basically pulled +$150K in the seconds. He was a handy basketballer.
The NBL may never be able to match the cash the AFL offers, but the NBL can always try to catch the "offcuts" of players who don't quite make the grade of AFL, or "re-divert" them back to NBL.
The AFLw has been outstanding in stealing female players from other sports to their competition.