Layovers are usually 6 hours ish. Some may be more or less. Again, these guys know the drill. They are here working hard for a better future. I haven't once heard an Eagle Jet FO complain about the situation. Not saying this because it's a good situation, rather, it's an opportunity for them to get where they want to go and they know it.
No one's forcing this upon them. More often than not I come back to base and see the FO's getting into much nicer cars than mine.