Ok I think I found it here, click the "Regular season tiebreakers" box at the bottom:
https://help.yahoo.com/kb/head-to-head-scoring-yahoo-fantasy-sln6212.html

(tldr: you were right)

Wild card

In Fantasy Football:
Total fantasy points (season total).
Fantasy points scored in the most recently completed matchup.
Fantasy points scored in the matchup two weeks prior (this continues until the tie is broken).

Division championship tie

The division winning percentage is used first.
If there's still a tie, the wild card method (above) is used.
If there's more than 2 managers tied for division champion, once the winner is determined, the remaining >teams will use the wild card method only (division winning percentage is ignored).