I wouldn't relocate Bulldogs. They represent the West of Melbourne which is still an important growth area as well as rural West Victoria e.g. Ballarat.While we’re doing fantasy:
Suns merge with Southport to become GC Sharks
GWS rebrand as Western Sydney Giants
Tassie Devils enter, so that’s 19 teams.
Roos to Canberra, Bulldogs to Moreton Bay (so Brisbane 2), Saints to Newcastle
Perth Miners team 20.
Future expansion: Auckland Pirates and 3rd Adelaide or 3rd Sydney team.
Possibly after that, Darwin Dingoes and Cairns Crocodiles or a Northern based side playing 7 Darwin/4 Cairns IF transport is much faster in the future. So could be Northern team + 3rd Adelaide side.
So a max of 22-24 teams, single tier comp, top 10 or 12 finals system, no wildcard round.