I think what's been shown over the last few years is that you need to have a list that's been thereabouts for a while. I'll go back to 2007.
Geelong - Finals in 04,05. No finals in 06. Flag 07. Rest is history.
Hawthorn - Finals in 07, flag in 08 (great recruiting), finals 10 and 11, rest is history.
Bulldogs - Finals in 15, flag 16.
Richmond - Finals 13,14,15. No finals 16, flag 17.
Sydney have been a side that's had sustained success from 03-17 in terms of finals.
North - Fairly frequent finals appearances since 07. 3 Preliminary finals.
As far as Melbourne and St Kilda? Well I think history shows that we both need to play finals for at least 2 years before we can go all the way, or at least make a GF. Adelaide are a good example as well.
I think if Melbourne with this list, then finals is mandatory in 18 & 19, I'd be looking at a flag potentially by 2020-2021. I think that's realistic. Plenty and plenty of experience into our young list.
I think next year we will see the WB, GWS, Port or West Coast win the flag - teams that are 'thereabouts' and have been for a while now. Obviously Adelaide and Richmond are in the hunt as well.
I also think North, Collingwood and Hawthorn will surge faster than people expect.