I've watched a bit of footy over the past 5 or 6 years in both the Hills country comp and in the amateur league. The styles of footy are completely different and hard to compare,but if I had to this is how I would see it.
IMO

Echunga, Birdwood, Kersbrook would be pretty competitive in Div 5, probably in the top 4, but I would suggest they would struggle in the div 4 comp.
Correct me if I am wrong, and I know it is only pre-season and a completely different format of a game, but didn't Plympton come up and play in the 20/20 last year and win it. I believe they played off in the grand final of the div 5 comp last year, with only 11 wins from 18 in the minor round.
I think Gum, Meadows and Nairne would struggle in div 5, and would probably only be middle of the road in div 6. There is some pretty handy footballers running around in div 6, and believe it or not, most of those clubs are getting 30+ guys a night on the training track right from the middle of November.
Kangarilla and Maccy would again be in the top 4 in the div 7 comp, and I'm pretty sure Sedan and Callington would really struggle in the C grade comp.
Comment how you like, this is only my opinion from my observations, but would be interested to hear what you think.