The extreme case actually seems good; pair doctoring where shifts start four hours apart, so you spend the first half of your shift with one doctor, and the second half with another.

Maybe instead do 2 x three hours, and give doctors really reasonable work hours or time to keep up on current research.

I fear the conclusion to that would be managers saying "what are all these doctors doing, we need to lay 3/4ths of them off and make the rest work twice as much for 50% more pay!"