Having been involved with playing and running a club in the lower Divisions, I'm not surprised at the fluctuations. For example:
I assume that Redfield OB don't have a lot of Pacific Islander or Maori lads in their club
Because I'm here to tell you St George had a shitload of Samoans and I know from experience that other clubs, particularly in the lower divisions, rise and fall quite quickly when your core strength comes from any of our well-tanned brothers from across the seas. For Islander/Maori guys, it can be as simple as following one of their better players to another club, or even the guys who provide the lift to the game. It isn't always about money.
On Grand Final Day 2010, 40 Renegades took the field in two grades. The next year only 10 of them came back to the club, mostly white guys, while our 2nd Grade Premier Samoans all went to the Emus to play 3s or 4s (mostly both, every week), and a lot of the Maori First Grade guys had been there three years and went to look for greener grass. Our record that year is hardly stellar, though at least we had one win in each grade.
The other big issue is volunteer burnout - everyone needs to chip in as well as paying their rego money, but some of the "stars" didn't see it that way because they didn't do that back home (cuz), and thought they were contributing enough through scoring tries as well as helping divest the pub of all that excess free beer.
Its great that some teams can come up and really show how its done, but for most clubs below Div 3 it is an immense struggle, particularly when you need to secure a council ground for half a day for a minority sport where they could get any number of soccer, loig, or AFL clubs
Ultimately, Subbies give zero fucks about you unless you're in a top Division or providing awesomeness - Tim Richards et al loved us in 2007 when our First Grade dominated the competition in the middle of a loig heartland. When the 2011 implosion happened they could not even fathom why - in four years we had 250 players registered, with new faces every year, but couldn't retain them despite the committee giving a lot of them free reign to do as they pleased while not contributing.
I sent them a long document with suggestions, but they've so far ignored it in favour of facing east and smiling at what they call progress.