The non-Sydney rivalries that I mentioned above get massive crowds and don't need the universe, weather, competitiveness etc to align to do so. Would you like to know why? Because they are the biggest and most well-attended rivalies in the game.
Guarantee the weather is very important and also competitiveness. Those factors are particularly vital. Funnily it's the derbies in SYDNEY that sustain various clubs when having a bad run. But no matter what : the weather and time of play is crucial !