[@Mistress Dizzy]

I honestly don't see why you can't/shouldn't.

Edit: I understand the bit about 'Standby' roles, and having a medical doctor and a policy about not having sconds, I can see how your role could be limited. However, I do have a few scenarios or 'role-hooks' in mind that would allow small instances where people would have the ability to 'task' outside their profession.

It mostly relies on them having hands, eyes, and able to understand sequences of direction.