2 quick clarifications on this.
For Group B, Vancouver would need to win by a score of 1-0. From there it would go to disciplinary points for the tiebreaker with Chicago, which seems likely if my calculations there are correct. I have us with 63 disciplinary points so far and Chicago with 51 points through 2 games. Fouls are 1 point, yellow cards 3, 2nd yellows/reds 7, coach dismissal is 7. It also lists "any supplemental discipline" as 8 points. I'm not completely sure if that applies to the fine Taty received for his dive earlier. My calculation is not including those 8 points at the moment.
I think I was wrong on the DC/Montreal possibility. The standings tiebreakers within groups are different from those for the 3rd place wildcards and I mixed those up. Within groups, it goes 1. Points 2. Wins 3. Goal Differential. For the wildcards, Wins is removed. Thus, if the Group C possibility doesn't really exist because a DC win puts, them at 5 points, a draw puts them at 3 with a GD of 0, and a Montreal win gives them a GD of -1.