Leaving Toronto out of this scenario for simplicity.
But say the Mariners go 6-4 (winning 4 out of 7 against Tex and 2 against us), the Rangers 6-4 (sweeping the Angels and losing 4 of 7 to the Ms), and we go 5-4 (Winning 2 against the Royals and DBacks and 1 against the M's). That would leave us all at 90 wins.
I think the Mariners would win the division in that scenario and we would win the tie breaker against the Rangers for a wild card spot.
Don't even want to think about what happens if all 4 teams (Toronto, Seattle, Texas, and us) finish at 90 wins. Maybe intradivision would come into play there and Toronto would miss out?
But, what all that shows is that the wild card magic number of 6 means that we need to win 6 games to guarantee a playoff spot. So, don't count on the wild card magic number dropping by two if we win and another team loses.
If we win only 5 games there is a possibility we miss the playoffs. Win less than 5 then we better hope that one of the Ms/Rangers sweep the other (or that the Blue Jays fall apart)
I think I need another drink after all that...