Depends on how you look at it. Playing crap teams is probably not the best preparation for a tough finals series. I'd rather play more quality teams. If your aim is to win the grand final then you need to beat the best teams all year. Having an easy draw might give you a few extra wins and help you make the finals but finals footy usually sorts it all out pretty quickly (look at Wyndemvale this year).
I agree, if you are going to win it you have to beat everyone and the match hardness and conditioning by playing the harder sides should hold teams in good stead for finals.
Only thing it does do though is it makes the teams with an easy draws tilt at the flag a bit easier if it helps them to a double chance position. Then a bit of luck with injuries at the right time and these teams are half way to a grand final.
I suppose like WVale and West last year the benefits of playing an easier year cost them both in finals as playing stronger teams is a lot different to 30 goal wins over lower teams.