Ah, Adelaide Oval......now you're talking my territory.
Is the oval suited to rugby league? Put simply......no its not. There isn't movable seating so spectators are at least 30 metres from the sidelines (forget the pictures shown during Australia's 2022 WC bid because that rectangle pitch with movable stands never happened). The A-League has played games there with Adelaide United and the complaints came thick and fast from spectators, especially with the decision to surround 3 sides of the pitch with electronic advertising boards. All that did was actually block the view of the spectators in the lower bowl.
Then there is another problem. Because Adelaide has two teams in the AFL the oval is used every single weekend during the football season. Both teams bitched and moaned about a once off soccer game being played there last year, can you imagine the outcry if there was a rugby league team that used it every other week?
If, and only if, a team was ever going to start in Adelaide or relocate to Adelaide, Coopers Stadium is much better suited despite only being able to hold 17,000.
With a capacity of 53,583 the Adelaide Oval would be good for one off games like an Origin or test match, but that is about it.
Realistically though, as much as I would love to see it, I would honestly prefer Manly stays at Brookie.