There's a simple solution to this problem, but it won't suit the bean counters. Simply legislate that anyone in any safety critical job whether it's flying a plane, controlling a chemical plant, driving a hazardous goods truck or runnig a nuclear power plant, cannot have more than one job (relatively simple to track via social security/National Insurance number & tax records). Likewise limit them to a maximum sixteen hour duty day with a 1.5 to 1.0 rest ratio, and a maximum 48 hour week averaged over four consecutive weeks.
It'd mean employing more staff, paying decent wages to the guys at the sharp end, rather than the bean counters who are after all carried on the backs of the folks doing the work. Above all it should mean better scheduling of shifts and duty rosters.
Tiredness is not purely an aviation issue. for example, the oil refinery almost next door to me changed hands three years ago. Under the previous multinational owner, the process operators worked on a rotating four shift system of ten days dayshift, backshift & nightshift with a day off between shifts followed by ten days off. Now under private ownership, it's been reduced to a two week 12 hr dayshift, nightshift regime, a day between shift changes and only a five day rest period. Holidays are now very difficult for guys to get as they need to get someone to cover for them from a much smaller pool of guys on their five days off rather than the bigger number available from a ten day rest period.