As said above Saints, Cats and Hawks matches could see losses for Collingwood. Plus Carlton can give them a real run for their money and even Richmond with their form and a bit of rivalry could stick it right up to the Pies. Also Essendon is another team that could find a way to upset them. The most reallistic result is 4-3 for Collingwood though,which would mean we need to win every game to pass them. Unlikely but still a chance.
I tried it myself and the Dogs do not pass the Pies with 6 wins v 4, which is not surprising since we are 10 points behind.
I was surpised in my scenario that Melbourne made the 8 with just 9.5 wins, with Sydney, Richmond and North on 9 wins. Of course results won't fall the way I quickly guessed them, but 9 to 10 wins will possibly snare eigth spot.