Hot and Heavy,
Yep, various types and ranks work hard or not according to the MANAGEMENT decisions of the era!
The contract is not all to blame, we have ways of being quite efficient, way more so than 20-40 years ago ( retirees when I joined probably averaged 350-450 hours per year!).
Even though I was on the 900 year limit for a few years my average including numerous courses, leave ( and most of my long service at half pay) is a little under 650 per year over 26 years.
There is little to stop us doing close to maximums allowing for reserve, leave etc.
The company does not do this for any number of reasons - it is not the PILOT's fault!
If other managers had made different decisions you may have seen a good fleet mix going to a larger mix of cities flown by engaged pilots flying more hours than now and everyone making money!