Some good insight Fletch.
We're operating in a model that welds a club together for the most part (women's excepted for now) and expects that cohesion to be a cornerstone of what "club" means.
Contrast this to other sports who tend to participate more at team level (league, soccer, Aussie rules).
Our model is slightly easier for management - operating on a skeleton crew of volunteers, mostly - means having everyone in one place is far easier. The distributed model requires a bit more volunteer support and usually finance. Organising venues would be a little more tricky as well.
Others have posted here a combined 3-grade model for the lower divisions where everyone from single to three grade clubs are part of the same comp, having realised they will never have the capacity to grow to first/second division level