Several of these rostered patterns have been the subject of many ASRs, and MORs. When an MOR is filed, CAD are notified, so they are well aware of the situation, and it is causing the company alot of grief.
But so far the response from CAD has been to attempt to cover themselves by accusing some aircrew of operating while fatigued !
Rice Pudding is correct that as long as the duty falls within the FTLs then no rules have technically been broken.
Tread carefully with this. Fatigue is a subject that is rarely mentioned in accident reports, and flies in the face of productivity. It is far easier to make an example of an individual for alledgedly operating while fatigued than to fix the problem and reduce productivity.