Should have been a 40,000 seater
Why? So there can be even more empty seats? This stadium will surely lift the Storms average attendance higher than it ever has been but even if they get a 20K ave which would be excellent, there'll still be more than 10K empty seats so why would you want nearly 10 more thousand on top of that?
The other major tennant the Victory had a highest season average a few years ago of 24,500 with an ave of 19,822 over their 5 years in existence so again there's no valid reason to have 40,000 seats. The Victory will move a couple games to Etihad against Sydney and Adelaide i think it is but even then they've struggled in the last couple of years to draw a crowd bigger than what the 31K new stadium will be.
Even come finals time if the Storm
maybe need a few thousand more seats then that'd be even better because you'll be gauranteed they get a sell out which is only a good thing. The point is you wouldn't need 40k seats for well over 90% of the time so why have them in the first place?