Okay, I misread Strikers for Reds. Those are all traditional sports.
I would think an Adelaide RL team would be more comparable to the Reds.
I don't think so, Soccer attendances across the country are always pretty bad unless you're on the top of the ladder.
Adelaide and Perth have the best sports attendances across Australia, if you go per capita they absolutely wallop every other state and it isn't for some unknown reason they just have a strong attendance culture.
The Reds and Rams both started out great and were victims of the Super League War. The Western Force used to bring in 20,000+ on the regular but aside from ARU and their farcical operations, people in Adelaide and Perth will turn on you if they feel they're being set up to fail (The Force absolutely were given they had a salary cap imposed on them that was $2 million less than other teams, ironically the same as that stupid clause thrust on the Reds to pay all visiting teams travel and accommodation expenses).
Put quite simply any time a sport in the West and South is given an honest and fair chance they show up. You only have to look at Basketball, that's not a traditional sport in Australia and get the Perth Wildcats get crowds around the 12-13,000 mark in a 15,000 seat arena and Adelaide filled their old 8,000 seater stadium so much that they've been upgraded to a 12,000 seater for this next season.
I have absolute faith that given a fair go WA and SA will not just get behind expansion teams but a decade of consistent support from the NRL and you'll have another 2 Broncos on your hands.