Let me throw a few more numbers into the equation...
A company I used to work for had a 4 on / 4 off shift pattern plus overtime.
The senior management decided to do away with overtime and in compensation increased the salary by a couple of thousand a year.
But here's the real sting in the tail...
All 4 Ops Controllers had 25 days holiday a year , which meant each person had to cover someone else for 25 extra shifts.
This meant that although you were entitled to 25 days leave, you also had to work an extra 25 days.
Management refused to see the staff point of view that this arrangement meant too many working hours/days per year.
Within 6 months 3 out of 4 Controllers voted with their feet and departed.
I now work 4 on 4 off again, but without the nazi regime and find it suits my lifestyle very well.