Wouldn't it be better to transition those people with the longest commutes first, as they use the most energy and have consistent needs?

No, because stop-and-go gets the most benefit from regeneration. One full EV for one long commuter who also drives around town, or 7 PHEVs for people that commute shorter but also drive around town.

Long haul stuff should probably be transitioned last both with commuting and things like trucking (stop and go things like trash and delivery and bus service makes a lot more sense than targeting cross-country trucking first).