As a bloke who used to live in Watsonia, and knowing a fair few lads who play or did play for them, it is common knowledge that Watsonia is still on its knees after failing to pay their players two seasons ago. They had a mass exodus from the club of a lot of quality seasoned players, and they have been the whipping boys since.
Don't know about Div 3 NFL being the same as D4 ammos though! From what I have seen in the past it would be more like D3, with the top tier teams giving D2 clubs a run for their money. Gauge the performances from the two D2 sides on that and see where they and Watsonia are at!
Lower Plenty played MHSOB in a praccy match last season when they were B grade and beat them by 120 points! Lower were runners up for Div 2 NFL.