1) you can always move to bigger planes; it’s harder to move down. It’s just foolish to give up two years of flexibility to save maybe 2 months of commuting

2) the sfo 756 base is quite small. 320/737 roughly 2x and 3x bigger with more variety of flying. New hires will have more flexibility with a bigger category.

2 is the biggest reason. EWR 756 would be a different story.