I think OP means combined program vs neuro categorical...and whether it's kosher to apply to both tracks at the same institution.
I believe there are only 2 combined programs, at Tulane and Wisconsin.
For NCC/neurohospitalist, I'd imagine a combined program would prepare you more for that track. That's one reason I'm considering combined programs. However, I wonder if there'd be any utility in just loading up MS4 year with an IM sub-I, ICU, cards, pulm electives...