Short Answer: While it’s two different documents/roles it can be the same person wearing both hats.
The document for handling financial matters is called a Durable Power of Attorney and the Health Care Surrogate Designation is for healthcare decisions when you are unable but there’s an expectation of survival.
I usually approach it from the perspective that they are very different roles and often different loved ones might be better suited for one rather than the other. I tell my client’s that they shouldn’t feel it HAS to be the same person but it absolutely can be.