Again because I'm weird, here is how certain 3 team tiebreakers for 1 spot involving the Cubs would look like. Gonna leave off ARI since there's still a lot of fluidity and Philly because its still a long shot that the Cubs, Phillies and another team are fighting for WC3.
CHC/CIN/SF:
CHC is 5-1 vs. SF, 6-7 vs CIN, SF is 4-3 vs CIN. Since no team won the H2H over the other 2 teams, its best winning % against other opponents. Cubs would be 11-8, Giants 5-8, Reds 10-10 so the Cubs would win this tiebreaker
CHC/CIN/MIA:
CHC is 2-4 vs. MIA and 6-7 vs. CIN. MIA and CIN tied 3-3. Since no team won H2H over the other 2 teams, Cubs would be 8-11, MIA 7-5, CIN 10-9 so Miami would win this tiebreaker
CHC/SF/MIA:
CHC is 2-4 vs. MIA and 5-1 vs. SF. SF is 3-3 vs. MIA. Again goes to winning % against others. CHC is 7-5, SF is 4-8, MIA is 7-5. At this point it reverts to H2H between CHC and MIA and Miami would win this tiebreaker (if they are playing for 2 spots then the Cubs would also slide in as WC3 and Miami WC2)
Looking at Arizona high level they are currently 3-1 vs. CHC (3 to play), 2-4 vs. MIA, 5-6 vs SF (2 to play), 3-4 vs. CIN