Running and Sally, can I ask if I have understood the arguments correctly, because as several people have said it can be hard to pick out what's salient.
Do I understand correctly, that the (main) issue JDs have with the new contract, is that it incentivises employers to schedule more hours per week. And this also leads to more erratic combinations of hours (not a straight fortnight of nights only, followed by a fortnight of days only, for example)?
When basic pay is comparatively low, and overtime rate is comparatively high, an employer has an incentive to employ a greater number of people to cover the rota (this is true in a factory as well).
But when basic pay goes up, and overtime rates go down, the employer has a disincentive to take on more people (higher basic rate), and will suffer less financial penalty for scheduling the existing employees to work more hours.
Is that essentially what's happening here?
(Although obviously more complicated, given the supply of suitably skilled labour may be different for a factory and for a hospital.)