In the past, there have been procedures for a three-way tie. IIRC, there is some sort of draw, and it’s all single elimination. The winner chooses between playing two games at home or one on the road. If they choose the one on the road, the other two teams flip a coin for home advantage. The winner of that game plays the team that sat out.
If the winner decides to play two games at home, the other two flip to see who plays them first.
For a four-way tie, they’d draw up two games the first day, leading to the championship the next day as the winning teams play.
My guess is that the NL West teams would have two additional games - one between teams A&B, then one between the winner of that game and team C. Team C would be the one that won a series of coin flips earlier. The winner of the second game would be the division winner.
Then, because those games go on the books as regular season games, the Braves would be the wild card winner, because both of the losing teams would wind up with worse records than the Braves.
They do count as regular season games, but the procedure is correct. This was changed after a 3 way tie either gave or almost gave (Don’t quite remember the teams Mets, Astros, Reds maybe?) the wild card automatically to the team not part of the division race.
I would have to research that particular situation, but it’s moot now because it’s impossible for the Giants, Padres, and Rockies to finish with the same record (the Rockies are 5 games back with 6 to play, and the Giants/Padres are guaranteed to win at least 3 games between them).