Interesting thread.
You always have to be careful in industries where they put you in a uniform. Usually, it means they are going to shaft you in some way: think security guards, armed forces, cabin crew, pilots.....
Do all those complaining of fatigue actually put in fatigue reports? That would be a start, (and I include myself in that). Fatigue when driving home is still fatigue caused by the rostering.
When I told my previous airline boss that working 6 on 2 off and starting on earlies, finishing on lates, was so fatiguing, he said you don't work that pattern as much as you think you do. (We did, so I left).